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Different Phases (different + phase)
Selected AbstractsPartnering for Greater Success: Local Stakeholders and Research in Tropical Biology and ConservationBIOTROPICA, Issue 5 2009Karen A. Kainer ABSTRACT Local communities are important stakeholders in resource management and conservation efforts, particularly in the developing world. Although evidence is mixed in suggesting that these resident stakeholders are optimal forest stewards, it is highly unlikely that large tracts of tropical forests will be conserved without engaging local people who depend on them daily for their livelihoods. Stakeholders, who reside in biodiverse ecosystems like tropical forests, are the largest direct users and ultimate decision-makers of forest fate, can be important investors in conservation, harbor local ecological knowledge that complements Western science and frequently have long-term legitimate claims on lands where they reside. Research partnerships with local stakeholders can increase research relevance, enhance knowledge exchange and result in greater conservation success. Different phases of the research cycle present distinct opportunities for partnership, with flexibility in timing, approaches and strategies depending on researcher and local stakeholder needs and interests. Despite being the last step in the research process, dissemination of results can be the best starting point for researchers interested in experimenting with local stakeholder engagement. Still, tropical biologists might not choose to partner with local people because of lack of institutional rewards, insufficient training in stakeholder engagement, insecure research infrastructure in community settings, and time and funding limitations. Although not appropriate in all cases and despite significant challenges, some biological scientists and research institutions have successfully engaged local stakeholders in the research process, proving mutually beneficial for investigators and local people alike and resulting in important innovations in tropical biology and conservation. [source] No experimental evidence for local competition in the nestling phase as a driving force for density-dependent avian clutch sizeJOURNAL OF ANIMAL ECOLOGY, Issue 4 2009Marion Nicolaus Summary 1In birds, local competition for food between pairs during the nestling phase may affect nestling growth and survival. A decrease in clutch size with an increase in breeding density could be an adaptive response to this competition. To investigate whether breeding density causally affected the clutch size of great tits (Parus major), we manipulated breeding density in three out of eight study plots by increasing nest-box densities. We expected clutch size in these plots to be reduced compared to that in control plots. 2We analysed both the effects of variation in annual mean density (between-year comparisons) and experimental density (within-year comparison between plots) on clutch size variation, the occurrence of second broods and nestling growth. We examined within-female variation in clutch size to determine whether individual responses explain the variation over years. 3Over the 11 years, population breeding density increased (from 0·33 to 0·50 pairs ha,1) while clutch size and the occurrence of second broods decreased (respectively from 10·0 to 8·5 eggs and from 0·39 to 0·05), consistent with a negative density-dependent effect for the whole population. Nestling growth showed a declining but nonsignificant trend over years. 4The decline in population clutch size over years was primarily explained by changes occurring within individuals rather than selective disappearance of individuals laying large clutches. 5Within years, breeding density differed significantly between manipulated plots (0·16 pairs ha,1 vs. 0·77 pairs ha,1) but clutch size, occurrence of second broods and nestling growth were not affected by the experimental treatment, resulting in a discrepancy between the effects of experimental and annual variation in density on reproduction. 6We discuss two hypotheses that could explain this discrepancy: (i) the decline in breeding performance over time was not due to density, but resulted from other, unknown factors. (ii) Density did cause the decline in breeding performance, but this was not due to local competition in the nestling phase. Instead, we suggest that competition acting in a different phase (e.g. before egg laying or after fledgling) was responsible for the density effect on clutch size among years. [source] The mother-offspring dyad and the immune systemACTA PAEDIATRICA, Issue 3 2000LÅ Hanson A. The mother and the fetus. The mother's immune system reacts against the fetus and there is therefore a risk of destruction of or damage to the fetus. We are now beginning to understand some of the mechanisms that protect the fetus, but, when these are defective, intrauterine growth retardation or abortions may ensue. However, the cytokines of this maternal immune response to the fetus also monitor different phases of pregnancy, starting with effects on the ovarium and involving preparation of the decidua for the implantation of the fertilized egg, the growth of the trophoblasts, the production of hormones important for the pregnancy and finally of the prostaglandins that induce delivery. B. The mother and the child. Human milk contains anti-idiotypic antibodies which after transfer to the offspring are capable of enhancing antibody responses. Human milk contains numerous leucocytes especially during early lactation. There is increasing evidence that milk lymphocytes are taken up by the breastfed infant, which seems to have become tolerant to maternal HLA. Breastfeeding mothers are therefore good donors of renal transplants to their breastfed offspring in adult age, too. Conclusion: It is suggested that the milk lymphocytes may be taken up by the offspring and that immunological information is thereby carried over from the mother. This mechanism may explain why breastfeeding seems to confer enhanced protection against infections also some years after the termination of breastfeeding. [source] Analytical Models for the Design of the LAPLAS ExperimentCONTRIBUTIONS TO PLASMA PHYSICS, Issue 4-5 2007A. R. Piriz Abstract We review the theoretical activity at the University of Castilla-LaMancha directed to the design of the LAPLAS (Laboratory of Planetary Sciences) experiment in the framework of the HEDgeHOB international collaboration. We have developed analytical models for the different phases of LAPLAS, including models for the implosion of the cylindrical shell target, for the generation of an annular focal spot by means of a high-frequency wobbler system and for the hydrodynamic instabilities that could affect the performance of the target implosion. These models have been complemented with one and two-dimensional numerical simulations and such a combination have allowed us to have a powerful tool available for the design of the experiments as well as for the interpretation of their results. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Microtubule-dependent organization of subcortical microfilaments in the early Drosophila embryoDEVELOPMENTAL DYNAMICS, Issue 3 2007Maria Giovanna Riparbelli Abstract Dynamic alterations in the spatial organization of cytoskeletal elements constitute a prominent morphological feature of the early, syncytial stages of embryogenesis in Drosophila. Here, we describe and characterize the dynamic behavior of cytoplasmic, subcortical microfilaments, which form a series of nucleus-associated structures, at different phases of the simultaneous nuclear division cycles characteristic of early Drosophila embryos. Remodeling of the cytoplasmic microfilament arrays takes place in parallel to the established cyclic reorganization of cortical microfilament structures. We provide evidence that the cortical and subcortical microfilament populations organize independently of each other, and in response to distinct instructive cues. Specifically, formation of subcortical microfilament structures appears to rely on, and spatially mirror, the organization of polarized microtubule arrays, while cortical microfilament restructuring constitutes a centrosome-dependent process. Genetic analysis identifies a requirement for SCAR, a key mediator of Arp2/3-based microfilament dynamics, in organization of subcortical microfilament structures. Developmental Dynamics 236:662,670, 2007. © 2007 Wiley-Liss, Inc. [source] Neuronal differentiation and long-term survival of newly generated cells in the olfactory midbrain of the adult spiny lobster, Panulirus argusDEVELOPMENTAL NEUROBIOLOGY, Issue 3 2001Manfred Schmidt Abstract The fate of continuously generated cells in the soma clusters of the olfactory midbrain of adult spiny lobsters, Panulirus argus, was investigated by in vivo pulse-chase experiments with the proliferation marker 5-bromo-2,-deoxyuridine (BrdU) combined with immunostainings for neuropeptides of mature neurons. A BrdU injection after a survival time (ST) of 14 h labeled about 100 nuclei in the lateral soma clusters (LC), comprised of projection neurons, and about 30 nuclei in the medial soma clusters (MC), comprised of local interneurons. The BrdU-positive nuclei were confined to small regions at the inside of these clusters, which also contain nuclei in different phases of mitosis and thus represent proliferative zones. After STs of 2 weeks or 3 months, the number of BrdU-positive nuclei was doubled, indicating a mitosis of all originally labeled cells. Dependent on ST, the BrdU-positive nuclei were translocated from the proliferative zones towards the outside of the clusters, where somata of mature neurons reside. Immunostainings with antibodies to the neuropeptides FMRFamide and substance P, both of which label a large portion of somata in the MC and a pair of giant neurons projecting into the LC, revealed that in both clusters the proliferative zones are surrounded by, but are themselves devoid of, labeling. In the MC, some BrdU-positive somata were double-labeled by the FMRFamide antibody after an ST of 3 months, and by the substance P antibody after STs of 6 and 11/14 months, but not after 3 months. In the LC, BrdU-positive somata after an ST of 3 months partially and after 6 and 11/14 months widely overlapped with the arborizations of the giant neurons, indicating the establishment of synaptic input. The experiments show that cells generated in proliferative zones in the LC and MC of adult spiny lobsters after a final mitosis differentiate into neurons within months, survive for at least 1 year, and are integrated into the circuitry of the olfactory midbrain. A new hypothesis about the mechanism of adult neurogenesis in the central olfactory pathway of decapod crustaceans is developed, linking it to neurogenesis during embryonic and larval development. © 2001 John Wiley & Sons, Inc. J Neurobiol 48: 181,203, 2001 [source] Effects of the Little Ice Age on avalanche boulder tongues in the French Alps (Massif des Ecrins)EARTH SURFACE PROCESSES AND LANDFORMS, Issue 5 2004Vincent 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] Viability study of HL60 cells in contact with commonly used microchip materialsELECTROPHORESIS, Issue 24 2006Floor Wolbers Abstract This paper presents a study in which different commonly used microchip materials (silicon oxide, borosilicate glass, and PDMS) were analyzed for their effect on human promyelocytic leukemic (HL60) cells. Copper-coated silicon was analyzed for its toxicity and therefore served as a positive control. With quantitative PCR, the expression of the proliferation marker Cyclin D1 and the apoptosis marker tissue transglutaminase were measured. Flow cytometry was used to analyze the distribution through the different phases of the cell cycle (propidium iodide, PI) and the apoptotic cascade (Annexin V in combination with PI). All microchip materials, with the exception of Cu, appeared to be suitable for HL60 cells, showing a ratio apoptosis/proliferation (Rap) comparable to materials used in conventional cell culture (polystyrene). These results were confirmed with cell cycle analysis and apoptosis studies. Precoating the microchip material surfaces with serum favor the proliferation, as demonstrated by a lower Rap as compared to uncoated surfaces. The Cu-coated surface appeared to be toxic for HL60 cells, showing over 90% decreased viability within 24,h. From these results, it can be concluded that the chosen protocol is suitable for selection of the cell culture material, and that the most commonly used microchip materials are compatible with HL60 culturing. [source] The characterization of functions involved in the establishment and maturation of Klebsiella pneumoniae in vitro biofilm reveals dual roles for surface exopolysaccharidesENVIRONMENTAL MICROBIOLOGY, Issue 3 2008Damien Balestrino Summary The ability to form biofilm is seen as an increasingly important colonization strategy among both pathogenic and environmental Klebsiella pneumoniae strains. The aim of the present study was to identify abiotic surface colonization factors of K. pneumoniae using different models at different phases of biofilm development. A 2200 K. pneumoniae mutant library previously obtained by signature-tagged mutagenesis was screened in static and dynamic culture models to detect clones impaired at early and/or mature stages of biofilm formation. A total of 28 mutants were affected during late phases of biofilm formation, whereas 16 mutants displayed early adhesion defect. These mutants corresponded to genes involved in potential cellular and DNA metabolism pathways and to membrane transport functions. Eight mutants were deficient in capsule or LPS production. Gene disruption and microscopic analyses showed that LPS is involved in initial adhesion on both glass and polyvinyl-chloride and the capsule required for the appropriate initial coverage of substratum and the construction of mature biofilm architecture. These results give new insight into the bacterial factors sequentially associated with the ability to colonize an abiotic surface and reveal the dual roles played by surface exopolysaccharides during K. pneumoniae biofilm formation. [source] Effects of handling on heat shock protein expression in rainbow trout (Oncorhynchus mykiss)ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2002Barbara Shayne Washburn Abstract As part of an effort to validate the use of heat shock proteins (HSPs) as biomarkers of exposure to and effects of contaminants, we evaluated the effect of two handling regimens on the induction of HSP 60 and 70 in rainbow trout (Oncorhynchus mykiss). Fish were acclimated to laboratory conditions for several weeks before the beginning of the experiment. Fish were then captured by net, placed in a cooler for 1 h while being transported in a truck, returned to their original tanks, then sacrificed 6 to 8 h later. Tricaine methane sulfonate (MS-222) was used during different phases of handling to reduce handling stress. Heat-stressed fish were included in the experiment as a positive control. Muscle, liver, gills, and heart were analyzed for HSP 60 and 70 by immunoblotting. We found no effect of any handling regimen on the induction of HSPs. These findings suggest that the capture and transport of fish for environmental monitoring purposes should not interfere with the use of stress proteins as biomarkers. [source] Theoretical framework for the distribution of trace metals among the operationally defined speciation phases of a sedimentENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2001René A. Nome Abstract The use of a model based on Langmuir's isotherm to evaluate the metal associated with separate geochemical phases of a sediment is proposed and its validity tested with sediments of certified composition. The model takes into account a standard procedure for a certified reference material (CRM601), which defines, experimentally, a set of sequential extractions that divide the sediment into four operational fractions. The derived equations allow the treatment of data from sediment of Flumendosa Lake, Italy, and certified material CRM601 and also allow the computation of corrected concentrations, i.e., the metal affinities for each fraction. Experimental values for Ni show its low sensitivity and an equal distribution among different phases, which suggests a similar adsorption mechanism in all cases. In the case of Cd, the corrected concentration in the Fe/Mn oxide phase is nine times higher than for the residual fraction. For sediment of the Bèsos River, Spain, results show the percentage distribution of Ni over different fractions. Affinity values for Ni on a Flumendosa Lake sediment have also been calculated. The present model is simple to apply and shows satisfactory agreement with experimental data. [source] Spontaneous periictal leaving behavior: A potential lateralizing sign in mesial temporal lobe epilepsyEPILEPSIA, Issue 6 2009Liri Jin Summary Purpose:, Seizure-related spontaneous leaving behavior (LB) is an uncommonly reported phenomenon. The aim of this study was to determine its frequency, clinical significance, and especially its lateralizing value. Methods:, We analyzed retrospectively the spontaneous periictal LB occurring in complex partial seizures (CPS) of 138 patients with medically refractory mesial temporal lobe epilepsy (MTLE) with excellent postoperative seizure outcome and pathologic finding of hippocampal sclerosis. The relation of LB occurring in different phases of CPS to the side of resection was investigated. Results:, The overall frequency of periictal LB was 8.3% of 517 CPS and 25.2% of 123 patients. Among the 12 patients with ictal LB, 9 patients had epileptogenic focus ipsilateral to language dominant side, whereas the remaining 3 had seizure onset in the nondominant side. Conversely, 8 of 11 patients with postictal LB had foci in the nondominant side, and only three patients' seizures originated in the dominant side. Therefore, it was more likely for patients with left MTLE to show ictal LB and for those with right foci to display postictal LB (p = 0.03). Conclusions:, LB may represent a potential lateralizing sign. When LB occurs ictally, it may indicate seizure onset in the dominant temporal lobe, and LB occurring postictally indicates nondominant side seizure onset in patients with MTLE. [source] Dynamic Variations of Local Cerebral Blood Flow in Maximal Electroshock Seizures in the RatEPILEPSIA, Issue 10 2002Véronique André Summary: ,Purpose: Measurement of cerebral blood flow is routinely used to locate the areas involved in generation and spread of seizures in epilepsy patients. Because the nature of the hyperperfused regions varies with the timing of injection of tracer, in this study, we used a rat model of maximal electroshock seizures to follow up the time-dependent changes in the distribution of seizure-induced cerebral blood flow (CBF) changes. Methods: CBF was measured by the quantitative autoradiographic [14C]iodoantipyrine technique over a 30-s duration. The tracer was injected either at 15 s before seizure induction, simultaneous with the application of the electroshock (tonic phase), at the onset of the clonic phase, or at 3 and 6 min after the seizure (postictal phase). Results: Rates of CBF underwent dynamic changes during the different phases of seizure activity and largely increased over control levels (,400%) in the 45 regions studied during all phases of the seizure (first 3 times). CBF remained higher than control levels in 35 and 15 areas at 3 and 6 min after the seizure, respectively. Conclusions: The distribution of maximal CBF increases showed a good correlation with their known involvement in the circuits underlying the clinical expression of the different types of seizure activity, tonic versus clonic. [source] Immunisation with BCG and recombinant MVA85A induces long-lasting, polyfunctional Mycobacterium tuberculosis -specific CD4+ memory T lymphocyte populationsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 11 2007Natalie Abstract In the search for effective vaccines against intracellular pathogens such as HIV, tuberculosis and malaria, recombinant viral vectors are increasingly being used to boost previously primed T cell responses. Published data have shown prime-boost vaccination with BCG-MVA85A (modified vaccinia virus Ankara expressing antigen 85A) to be highly immunogenic in humans as measured by ex vivo IFN-, ELISPOT. Here, we used polychromatic flow cytometry to investigate the phenotypic and functional profile of these vaccine-induced Mycobacterium tuberculosis (M.tb) antigen 85A-specific responses in greater detail. Promisingly, antigen 85A-specific CD4+ T cells were found to be highly polyfunctional, producing IFN-,, TNF-,, IL-2 and MIP-1,. Surface staining showed the responding CD4+ T cells to be relatively immature (CD45RO+ CD27intCD57,); this observation was supported by the robust proliferative responses observed following antigenic stimulation. Furthermore, these phenotypic and functional properties were independent of clonotypic composition and epitope specificity, which was maintained through the different phases of the vaccine-induced immune response. Overall, these data strongly support the use of MVA85A in humans as a boosting agent to expand polyfunctional M.tb -specific CD4+ T cells capable of significant secondary responses. [source] Minerals as Model Compounds for Cu/ZnO Catalyst Precursors: Structural and Thermal Properties and IR Spectra of Mineral and Synthetic (Zincian) Malachite, Rosasite and Aurichalcite and a Catalyst Precursor MixtureEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 10 2009Malte Behrens Abstract The Cu/ZnO system is a model for Cu/ZnO/Al2O3 catalysts, which are employed industrially for the synthesis of methanol. These catalysts are usually prepared from mixed basic carbonate precursors. A complex phase mixture, with constituents structurally related to the minerals rosasite andaurichalcite, is present at the industrially applied composition (Cu/Zn , 70:30). Using minerals and phase-pure synthetic samples as references, a comprehensive characterisation of such a phase mixture, including the determination of the individual compositions of the different phases, has been attempted by complementary analytical laboratory techniques (XRD, TGA, IR). The results are critically discussed in light of the complexity of the system. A thermally very stable carbonate species , well-known for mixed synthetic systems , is also detected for the mineral reference samples. Significant amounts of amorphous phases are found to be present in the synthetic zincian malachite sample but not in synthetic aurichalcite or the catalyst precursor. A simplified explanation for the shift of the characteristic 20 reflection of the malachite structure as a function of Zn incorporation based on the varying average Jahn,Teller distortion of the MO6 octahedra is proposed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Inter-hemispheric inhibition is impaired in mirror dystoniaEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 8 2009S. Beck Abstract Surround inhibition, a neural mechanism relevant for skilled motor behavior, has been shown to be deficient in the affected primary motor cortex (M1) in patients with focal hand dystonia (FHD). Even in unilateral FHD, however, electrophysiological and neuroimaging studies have provided evidence for bilateral M1 abnormalities. Clinically, the presence of mirror dystonia, dystonic posturing when the opposite hand is moved, also suggests abnormal interhemispheric interaction. To assess whether a loss of inter-hemispheric inhibition (IHI) may contribute to the reduced surround inhibition, IHI towards the affected or dominant M1 was examined in 13 patients with FHD (seven patients with and six patients without mirror dystonia, all affected on the right hand) and 12 right-handed, age-matched healthy controls (CON group). IHI was tested at rest and during three different phases of a right index finger movement in a synergistic, as well as in a neighboring, relaxed muscle. There was a trend for a selective loss of IHI between the homologous surrounding muscles in the phase 50 ms before electromyogram onset in patients with FHD. Post hoc analysis revealed that this effect was due to a loss of IHI in the patients with FHD with mirror dystonia, while patients without mirror dystonia did not show any difference in IHI modulation compared with healthy controls. We conclude that mirror dystonia may be due to impaired IHI towards neighboring muscles before movement onset. However, IHI does not seem to play a major role in the general pathophysiology of FHD. [source] Microstructural Characterization of Lamellar Features in TiAl by FIB Imaging,ADVANCED ENGINEERING MATERIALS, Issue 6 2010Dennis Peter A novel experimental procedure is introduced to determine phase fractions and the distribution of individual phases of TiAl-based two-phase alloys using the focused ion beam (FIB) technique. Two , -titanium aluminide alloys with a fine-grained duplex and a nearly lamellar microstructure are examined. The special FIB-based preparation procedure results in high contrast ion beam-induced images for all investigated alloys and allows to quantify the phase contents easily by automated microstructural analysis. Fine two-phase structures, e.g. lamellar colonies in , -TiAl, can be imaged in high resolution with respect to different phases. To validate the FIB-derived data, we compare them to results obtained with another method to determine phase fractions, electron back-scatter diffraction (EBSD). This direct comparison shows that the FIB-based technique generally provides slightly higher ,2 -fractions, and thus helps to overcome the limited lateral resolution near grain boundaries and interfaces associated with the conventional EBSD approach. Our study demonstrates that the FIB-based technique is a simple, fast, and more exact way to determine high resolution microstructural characteristics with respect to different phase constitutions in two-phase TiAl alloys and other such materials with fine, lamellar microstructures. [source] Annealing of Biodegradable Polymer Induced by Femtosecond Laser Micromachining,ADVANCED ENGINEERING MATERIALS, Issue 4 2010Wai Yee Yeong Abstract Femtosecond laser is a potential tool for net shape processing of biodegradable polymers. However, laser processing of polymeric material is still a challenge and the effects induced by laser ablation needs to be investigated. Poly(, -caprolactone) was micromachined at high fluence and the heat affected zone was characterized. Two different phases of microstructure, namely the annealed spherulite zone and the amorphous zone, are found. [source] Nanoindentation of a Pseudoelastic NiTiFe Shape Memory Alloy,ADVANCED ENGINEERING MATERIALS, Issue 1-2 2010Janine Pfetzing-Micklich Nanoindentation is a suitable tool for characterizing the local mechanical properties of shape memory alloys (SMA) and to study their pseudoelastic behavior. There is a special interest in indenting with different indenter tips (as not all tips are associated with strain states that predominantly induce the martensitic transformation) and in indenting at different temperatures, where different phases are present. In this study, we perform nanoindentation on a ternary NiTiFe SMA with different indenter tips and at various testing temperatures. For nanoindentation with spherical tips, load,displacement hystereses clearly indicate pseudoelastic behavior, whereas indentation with Berkovich tips results in more pronounced plastic deformation. Testing at different temperatures is associated with different volume fractions of austenite, martensite, and R-phase. The corresponding nanoindentation responses differ considerably in terms of pseudoelastic behavior. Best pseudoelastic recovery is found at testing temperatures close to the R-phase start temperature, even though this temperature is below the austenite finish temperature, which is a well-known lower temperature bound for full recovery in macroscopic tests. Our results are discussed considering micromechanical aspects and the interaction between stress-induced phase transformation and dislocation plasticity. [source] Distribution of SIBLING proteins in the organic and inorganic phases of rat dentin and boneEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 2 2008Bingzhen Huang The SIBLING protein family is a group of non-collagenous proteins (NCPs) that includes dentin sialophosphoprotein (DSPP), dentin matrix protein 1 (DMP1), bone sialoprotein (BSP), and osteopontin (OPN). In the present study, we compared these four proteins in different phases of rat dentin and bone. First, we extracted NCPs in the unmineralized matrices and cellular compartments using guanidium-HCl (G1). Second, we extracted NCPs closely associated with hydroxyapatite using an EDTA solution (E). Last, we extracted the remaining NCPs again with guanidium-HCl (G2). Each fraction of Q-Sepharose ion-exchange chromatography was analyzed using sodium dodecyl sulfate,polyacrylamide gel electrophoresis (SDS,PAGE), Stains-All stain, and with western immunoblotting. In dentin, the NH2 -terminal fragment of DSPP and its proteoglycan form were primarily present in the G1 extract, whereas the COOH-terminal fragment of DSPP was present exclusively in the E extract. The processed NH2 -terminal fragment of DMP1 was present in G1 and E extracts, whereas the COOH-terminal fragment of DMP1 existed mainly in the E extract. Bone sialoprotein was present in all three extracts of dentin and bone, whereas OPN was present only in the G1 and E extracts of bone. The difference in the distribution of the SIBLING proteins between organic and inorganic phases supports the belief that these molecular species play different roles in dentinogenesis and osteogenesis. [source] ORIGINAL ARTICLE: Probability of emergence of antimalarial resistance in different stages of the parasite life cycleEVOLUTIONARY APPLICATIONS (ELECTRONIC), Issue 1 2009Wirichada Pongtavornpinyo Abstract Understanding the evolution of drug resistance in malaria is a central area of study at the intersection of evolution and medicine. Antimalarial drug resistance is a major threat to malaria control and directly related to trends in malaria attributable mortality. Artemisinin combination therapies (ACT) are now recommended worldwide as first line treatment for uncomplicated malaria, and losing them to resistance would be a disaster for malaria control. Understanding the emergence and spread of antimalarial drug resistance in the context of different scenarios of antimalarial drug use is essential for the development of strategies protecting ACTs. In this study, we review the basic mechanisms of resistance emergence and describe several simple equations that can be used to estimate the probabilities of de novo resistance mutations at three stages of the parasite life cycle: sporozoite, hepatic merozoite and asexual blood stages; we discuss the factors that affect parasite survival in a single host in the context of different levels of antimalarial drug use, immunity and parasitaemia. We show that in the absence of drug effects, and despite very different parasite numbers, the probability of resistance emerging at each stage is very low and similar in all stages (for example per-infection probability of 10,10,10,9 if the per-parasite chance of mutation is 10,10 per asexual division). However, under the selective pressure provided by antimalarial treatment and particularly in the presence of hyperparasitaemia, the probability of resistance emerging in the blood stage of the parasite can be approximately five orders of magnitude higher than in the absence of drugs. Detailed models built upon these basic methods should allow us to assess the relative probabilities of resistance emergence in the different phases of the parasite life cycle. [source] Teaching and Learning with Therapists Who Work with Street Children and Their FamiliesFAMILY PROCESS, Issue 3 2010JANINE ROBERTS ED.D. Providing training for people working with some of the most marginalized families in Guatemala and Peru meant establishing credibility as a facilitator; entering organizations as a learner; cocreating training agendas; and working in a format that paralleled a strength-based, resilience focus in therapy. Strategies used for different phases of the work are detailed: multiple ways to gather information, shadowing staff, delivering topics on demand, and creating learning environments with a focus on families as teachers. Key processes included moving in and out of the role of facilitator and participant, entering into the trainings from different vantage points within the organizations, and designing activities with an eye to how they would impact work relationships of staff and clients. RESUMEN Brindar capacitación a personas que trabajan con algunas de las familias más marginadas de Guatemala y Perú implicó establecer credibilidad como facilitador; ingresar en organizaciones como alumno; co-crear agendas de capacitación y trabajar en un formato análogo a un enfoque basado en las virtudes y la resiliencia en terapia. Se detallan las estrategias utilizadas en las diferentes fases del trabajo: distintas maneras de reunir información, observación del personal, charlas a pedido, y creación de ambientes de aprendizaje haciendo hincapié en las familias como maestras. Los procesos clave consistieron en asumir y abandonar el rol de facilitador y participante, iniciar las capacitaciones desde diferentes posiciones de ventaja dentro de las organizaciones y diseñar actividades con miras a cómo repercutirían sobre las relaciones laborales del personal y los clientes. Palabras clave: capacitación colaborativa, niños que trabajan en la calle, terapia familiar en Latinoamérica [source] 13C-Labeled metabolic flux analysis of a fed-batch culture of elutriated Saccharomyces cerevisiaeFEMS YEAST RESEARCH, Issue 4 2007Roeland Costenoble Abstract This study addresses the question of whether observable changes in fluxes in the primary carbon metabolism of Saccharomyces cerevisiae occur between the different phases of the cell division cycle. To detect such changes by metabolic flux analysis, a 13C-labeling experiment was performed with a fed-batch culture inoculated with a partially synchronized cell population obtained through centrifugal elutriation. Such a culture exhibits dynamic changes in the fractions of cells in different cell cycle phases over time. The mass isotopomer distributions of free intracellular metabolites in central carbon metabolism were measured by liquid chromatography,mass spectrometry. For four time points during the culture, these distributions were used to obtain the best estimates for the metabolic fluxes. The obtained flux fits suggested that the optimally fitted split ratio for the pentose phosphate pathway changed by almost a factor of 2 up and down around a value of 0.27 during the experiment. Statistical analysis revealed that some of the fitted flux distributions for different time points were significantly different from each other, indicating that cell cycle-dependent variations in cytosolic metabolic fluxes indeed occurred. [source] Dynamics of yeast populations recovered from decaying leaves in a nonpolluted stream: a 2-year study on the effects of leaf litter type and decomposition timeFEMS YEAST RESEARCH, Issue 4 2007Ana Sampaio Abstract Here we report on the results of a survey of the yeast populations occurring on submerged leaves (alder, eucalyptus and oak) in a natural mountain stream, during different phases of their decomposition and through two consecutive years. Leaf litter mass loss, total yeast counts, Shannon,Weiner index (H,), yeast community structure and physiologic abilities were analyzed to evaluate the dynamics of yeast communities during decay. Seventy-two yeast taxa were recorded, and in all litter types, species of basidiomycetous affinity predominated over ascomycetous ones. Discriminant analysis of presence/absence data (yeast species) showed significant differences both among substrate types (P<0.0026) and with decomposition time (P<0.0001). Carbon and nitrogen source utilization by yeast strains also varied with the substrate (P<0.0001) and decomposition time (P<0.0001). Further conclusions were that: (1) all litter types have in common ubiquitous yeast species, such as Cryptococcus albidus, Debaryomyces hansenii and Rhodotorula glutinis, among the common 20 yeast species; (2) only a few species were dominant, and most species were rare, being recorded once or twice throughout decomposition; and (3) the order of yeast appearance, and their substrate assimilation patterns, strongly suggest a succession phenomenon. Finally, explanations for the distribution patterns and variations in yeast communities are discussed. [source] Conductive Nanostructures of MMX ChainsADVANCED FUNCTIONAL MATERIALS, Issue 9 2010Alejandro Guijarro Abstract Crystals of [Pt2(n -pentylCS2)4I] show a transition from semiconductor to metallic with the increase of the temperature (conductivity is 0.3,1.4,S,·,cm,1 at room temperature) and a second metallic,metallic transition at 330,K, inferred by electrical conductivity measurements. X-ray diffraction studies carried out at different temperatures (100, 298, and 350,K) confirm the presence of three different phases. The valence-ordering of these phases is analyzed using structural, magnetic, and electrical data. Density functional theory calculations allow a further analysis of the band structure derived for each phase. Nanostructures adsorbed on an insulating surface show electrical conductivity. These results suggest that MMX-polymer-based nanowires could be suitable for device applications. [source] Effect of two oral doses of 17,-estradiol associated with dydrogesterone on thrombin generation in healthy menopausal women: a randomized double-blind placebo-controlled studyFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 2 2010Alexandra Rousseau Abstract Oral hormone therapy is associated with an increased risk of venous thrombosis. Drug agencies recommend the use of the lowest efficient dose to treat menopausal symptoms for a better risk/ratio profile, although this profile has not been totally investigated yet. The aim of the study was to compare the effect of the standard dose of 17,-estradiol to a lower one on thrombin generation (TG). In a 2-month study, healthy menopausal women were randomized to receive daily 1mg or 2 mg of 17,-estradiol (E1, n = 24 and E2, n = 26; respectively) with 10 mg dydrogesterone or placebo (PL, n = 22). Plasma levels factors VII, X, VIII and II were assessed before and after treatment as well as Tissue factor triggered TG, which allows the investigation of the different phases of coagulation process. The peak of thrombin was higher in hormone therapy groups (E1: 42.39 ± 50.23 nm, E2: 31.08 ± 85.86 nm vs. 10.52 ± 40.63 nm in PL, P = 0.002 and P = 0.01). Time to reach the peak was also shortened (PL: 0.26 ± 0.69 min vs. E1: ,0.26 ± 0.80 min, E2: ,0.55 ± 0.79 min, P <10,3 for both comparisons) and mean rate index of the propagation phase of TG was significantly increased. Among the studied clotting factors, only the levels of FVII were significantly increased after treatment administration. The two doses of 17,-estradiol induced in a similar degree an acceleration of the initiation and propagation phase of tissue factor triggered thrombin generation and a significant increase of FVII coagulant activity. [source] Analysis of adobe wall composition at the Chaves-Hummingbird Site, New Mexico, by diffuse reflectance spectrophotometryGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 8 2007William Balsam This article investigates adobe wall construction materials utilized by prehistoric inhabitants of Chaves-Hummingbird Pueblo, an ancestral Pueblo village located ,20 miles west of Albuquerque, New Mexico. The walls were constructed with native clay-rich soils some time between approximately 1275,1450 A.D. Samples were analyzed with a diffuse reflectance spectrophotometer from the near ultraviolet (NUV) through the visible (VIS) and into the near infrared (NIR) region of the electromagnetic spectrum. Cluster analysis of samples from 275 adobe walls and 36 soil locations surrounding the pueblo room blocks indicates four clusters. Comparison of typical samples from the four clusters indicates that they are very similar and are distinguished by minor variations in the three primary spectrally determined components, Na-Ca montmorillonite, bentonite, and goethite. In general, clusters correspond with room construction episodes that are discernible through patterns of wall bonding and abutment recorded during the archaeological investigation of the site. This suggests that during different phases of construction the source of the wall adobe changed. Many of the soil samples are included in wall clusters and therefore reveal a potential source of material used for adobe, adjacent soils. However, not all the soil surrounding the pueblo grouped with wall clusters indicating a preference for certain soil types and that some soils were probably unsuitable for making adobe. Therefore, diversity in spectrally identified construction materials provides insights into source locations and possible construction preferences of the site inhabitants. © 2007 Wiley Periodicals, Inc. [source] Characterizing anthropic sediments in north European Neolithic settlements: An assessment from Skara Brae, OrkneyGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 3 2006Ian A. Simpson The creation of anthropic sediments, traditionally referred to under the blanket term midden, through the utilization of settlement waste materials in domestic settlement construction was first recognized during early excavations at the Orcadian Neolithic site of Skara Brae (V.G. Childe, 1931a; 1931b). Prior to the present study there has been no systematic attempt to identify the nature of these sediments at Skara Brae, whose likely occupation dates between ,3100 and 2500 B.C., or to assess whether different materials were incorporated into construction or varied with different phases of site formation. The opportunity to begin addressing these issues arose with the location of undisturbed sediment samples held in storage since the last site excavations of 1972,1973 (D.V. Clarke, 1976). Ten thin sections were manufactured from these samples, representing earlier and later phases of Neolithic settlement at Skara Brae. Observations using thin-section micromorphology, supported by total phosphorus and particle-size distribution analyses, suggest that both earlier and later settlement phases show accumulation of household waste dominated by fuel residues. These wastes may have been used to help stabilize wind-blown sand deposits during the later settlement phases. In addition, the use of clay material tempered with household waste is associated with wall construction. Animal manures are only evident in anthropic deposits on the edge of the main settlement site where composting may have been taking place, and there is no evidence for their use in site construction. The authors conclude by drawing attention to possible diverse uses of anthropic sediments in settlement construction at other Neolithic settlements in Orkney. © 2006 Wiley Periodicals, Inc. [source] Assessment and compensation of inconsistent coupling conditions in point-receiver land seismic dataGEOPHYSICAL PROSPECTING, Issue 1 2007Claudio Bagaini ABSTRACT We introduce a method to detect and compensate for inconsistent coupling conditions that arise during onshore seismic data acquisitions. The reflected seismic signals, the surface waves, or the ambient-noise records can be used for the evaluation of the different coupling conditions of closely spaced geophones. We derive frequency-dependent correction operators using a parametric approach based upon a simple model of the interaction between geophone and soil. The redundancy of the measurements available permits verification of the assumptions made on the input signals in order to derive the method and to assess the validity of the model used. The method requires point-receiver data in which the signals recorded by the individual geophones are digitized. We have verified the accuracy of the method by applying it to multicomponent ambient-noise records acquired during a field experiment in which the coupling conditions were controlled and modified during different phases of the experiment. We also applied the method to field data, which were acquired without the coupling conditions being controlled, and found that only a few geophones showed an anomalous behaviour. It was also found that the length of the noise records routinely acquired during commercial surveys is too short to provide enough statistics for the application of our method. [source] Glia-induced neuronal differentiation by transcriptional regulationGLIA, Issue 11 2007Christian Göritz Abstract There is increasing evidence that different phases of brain development depend on neuron,glia interactions including postnatal key events like synaptogenesis. To address how glial cells influence synapse development, we analyzed whether and how glia-derived factors affect gene expression in primary cultures of immunoisolated rat retinal ganglion cells (RGCs) by oligonucleotide microarrays. Our results show that the transcript pattern matched the developmental stage and characteristic properties of RGCs in vitro. Glia-conditioned medium (GCM) and cholesterol up- and downregulated a limited number of genes that influence the development of dendrites and synapses and regulate cholesterol and fatty acid metabolism. The oligonucleotide microarrays detected the transcriptional regulation of neuronal cholesterol homeostasis in response to GCM and cholesterol treatment. Surprisingly, our study revealed neuronal expression and glial regulation of matrix gla protein (Mgp). Together, our results suggest that glial cells promote different aspects of neuronal differentiation by regulating transcription of distinct classes of genes. © 2007 Wiley-Liss, Inc. [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||