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Manipulation
Kinds of Manipulation Terms modified by Manipulation Selected AbstractsEXPERIMENTAL MANIPULATION OF SEXUAL SELECTION PROMOTES GREATER MALE MATING CAPACITY BUT DOES NOT ALTER SPERM INVESTMENTEVOLUTION, Issue 4 2009Helen S. Crudgington Sexual selection theory makes clear predictions regarding male spermatogenic investment. To test these predictions we used experimental sexual selection in Drosophila pseudoobscura, a sperm heteromorphic species in which males produce both fertile and sterile sperm, the latter of which may function in postmating competition. Specifically, we determined whether the number and size of both sperm types, as well as relative testis mass and accessory gland size, increased with increased sperm competition risk and whether any fitness benefits could accrue from such changes. We found no effect of sexual selection history on either the number or size of either sperm morph, or on relative testis mass. However, males experiencing a greater opportunity for sexual selection evolved the largest accessory glands, had the greatest mating capacity, and sired the most progeny. These findings suggest that sterile sperm are not direct targets of sexual selection and that accessory gland size, rather than testis mass, appears to be an important determinant of male reproductive success. We briefly review the data from experimental sexual selection studies and find that testis mass may not be a frequent target of postcopulatory sexual selection and, even when it is, the resulting changes do not always improve fitness. [source] EJACULATE DEPLETION PATTERNS EVOLVE IN RESPONSE TO EXPERIMENTAL MANIPULATION OF SEX RATIO IN DROSOPHILA MELANOGASTEREVOLUTION, Issue 8 2007Jon R. Linklater We assessed the extent to which traits related to ejaculate investment have evolved in lines of Drosophila melanogaster that had an evolutionary history of maintenance at biased sex ratios. Measures of ejaculate investment were made in males that had been maintained at male-biased (MB) and female-biased (FB) adult sex ratios, in which levels of sperm competition were high and low, respectively. Theory predicts that when the risk of sperm competition is high and mating opportunities are rare (as they are for males in the MB populations), males should increase investment in their few matings. We therefore predicted that males from the MB lines would (1) exhibit increased investment in their first mating opportunities and (2) deplete their ejaculates at a faster rate when mating multiply, in comparison to FB males. To investigate these predictions we measured the single mating productivity of males from three replicates each of MB and FB lines mated to five wild-type virgin females in succession. In contrast to the first prediction, there was no evidence for differences in productivity between MB and FB line males in their first matings. The second prediction was upheld: mates of MB and FB males suffered increasingly reduced productivity with successive matings, but the decline was significantly more pronounced for MB than for FB males. There was a significant reduction in the size of the accessory glands and testes of males from the MB and FB regimes after five successive matings. However, the accessory glands, but not testes, of MB males became depleted at a significantly faster rate than those of FB males. The results show that male reproductive traits evolved in response to the level of sperm competition and suggest that the ability to maintain fertility over successive matings is associated with the rate of ejaculate, and particularly accessory gland, depletion. [source] MOLECULAR GENETIC MANIPULATION OF THE DIATOM THALASSIOSIRA PSEUDONANA (BACILLARIOPHYCEAE),JOURNAL OF PHYCOLOGY, Issue 5 2006Nicole Poulsen Here, we describe the first system for genetic transformation of Thalassiosira pseudonana (Hustedt) Hasle et Heimdal, the only diatom for which a complete genome sequence is presently available. This method is based on microparticle bombardment followed by selection of transformants using the antibiotic nourseothricin. It exhibits the highest transformation efficiency compared with transformation systems for other diatom species. To achieve the high transformation efficiency, it is important to allow recovery of the bombarded T. pseudonana cells in non-selective suspension culture before spreading on nourseothricin containing agar plates. It is demonstrated that T. pseudonana is readily susceptible to co-transformation allowing for the simultaneous introduction of a non-selective gene together with the selection marker gene. Both introduced genes are stably inherited even in the absence of the antibiotic selection pressure. We have developed two T. pseudonana -specific expression vectors that can drive constitutive expression (vector pTpfcp) and inducible expression (vector pTpNR) of introduced genes. In combination with the available genome data the T. pseudonana transformation system is expected to provide a powerful tool for functional genomics in diatoms. [source] Comparing Parameter Manipulation with Mouse, Pen, and Slider User InterfacesCOMPUTER GRAPHICS FORUM, Issue 3 2009Colin Swindells Abstract Visual fixation on one's tool(s) takes much attention away from one's primary task. Following the belief that the best tools ,disappear' and become invisible to the user, we present a study comparing visual fixations (eye gaze within locations on a graphical display) and performance for mouse, pen, and physical slider user interfaces. Participants conducted a controlled, yet representative, color matching task that required user interaction representative of many data exploration tasks such as parameter exploration of medical or fuel cell data. We demonstrate that users may spend up to 95% fewer visual fixations on physical sliders versus standard mouse and pen tools without any loss in performance for a generalized visual performance task. [source] Sketching and Composing Widgets for 3D ManipulationCOMPUTER GRAPHICS FORUM, Issue 2 2008Ryan Schmidt Abstract We present an interface for 3D object manipulation in which standard transformation tools are replaced with transient 3D widgets invoked by sketching context-dependent strokes. The widgets are automatically aligned to axes and planes determined by the user's stroke. Sketched pivot-points further expand the interaction vocabulary. Using gestural commands, these basic elements can be assembled into dynamic, user-constructed 3D transformation systems. We supplement precise widget interaction with techniques for coarse object positioning and snapping. Our approach, which is implemented within a broader sketch-based modeling system, also integrates an underlying "widget history" to enable the fluid transfer of widgets between objects. An evaluation indicates that users familiar with 3D manipulation concepts can be taught how to efficiently use our system in under an hour. [source] Direct Manipulation and Interactive Sculpting of PDE SurfacesCOMPUTER GRAPHICS FORUM, Issue 3 2000Haixia Du This paper presents an integrated approach and a unified algorithm that combine the benefits of PDE surfaces and powerful physics-based modeling techniques within one single modeling framework, in order to realize the full potential of PDE surfaces. We have developed a novel system that allows direct manipulation and interactive sculpting of PDE surfaces at arbitrary location, hence supporting various interactive techniques beyond the conventional boundary control. Our prototype software affords users to interactively modify point, normal, curvature, and arbitrary region of PDE surfaces in a predictable way. We employ several simple, yet effective numerical techniques including the finite-difference discretization of the PDE surface, the multigrid-like subdivision on the PDE surface, the mass-spring approximation of the elastic PDE surface, etc. to achieve real-time performance. In addition, our dynamic PDE surfaces can also be approximated using standard bivariate B-spline finite elements, which can subsequently be sculpted and deformed directly in real-time subject to intrinsic PDE constraints. Our experiments demonstrate many attractive advantages of our dynamic PDE formulation such as intuitive control, real-time feedback, and usability to the general public. [source] Art: Manipulation without endCRITICAL QUARTERLY, Issue 2 2001Mark Ryan First page of article [source] The Incidences of Chondritis and Perichondritis Associated With the Surgical Manipulation of Auricular CartilageDERMATOLOGIC SURGERY, Issue 1 2004Andrew L. Kaplan MD Background. The cartilage and soft tissues of the ear are frequently employed as donor sites for tissue used in the repair of defects of the nose and external ear after Mohs surgery. Enthusiasm for using these auricular donor sites is occasionally tempered by surgeons' concerns for the development of Pseudomonal suppurative chondritis, a complication that has been described to follow cartilage manipulation. Objective. To quantify the incidence of postoperative perichondritis and chondritis after Mohs reconstructions involving auricular cartilage manipulations. Methods. We retrospectively reviewed 341 Mohs reconstructions that involved cartilage and soft-tissue donor sites located on the ear. Procedures included full-thickness skin grafts (295) harvested from the conchal bowl and flap repairs (46) incorporating cartilage batten grafts from conchal or anthelix donor sites. When the perichondrium was compromised, patients were routinely prescribed perioperative prophylactic antibiotics with Pseudomonal coverage. Postoperative examinations were performed at 1 week and 4 to 12 weeks. Patients not seen in clinic were interviewed by telephone regarding complications. Results. Complete follow-up information was obtained in 337 of 341 (98.8%) cases. Inflammatory perichondritis was observed in 19 (5.6%) patients. There were no cases of suppurative chondritis. Conclusion. The incidence of inflammatory perichondritis is low after Mohs reconstructions involving auricular cartilage manipulation. When prophylactic antibiotics and appropriate operative technique are used, the historic concern for suppurative chondritis associated with these procedures is unwarranted. [source] Libertarian Free Will and CNC ManipulationDIALECTICA, Issue 3 2001Ishtiyaque Haji An agent who is the victim of covert and nonconstraining control (CNC) is unaware of being controlled and controllers get their way by manipulating the victims so that they willingly do what the controllers desire. Our primary objective is to argue that if cases of CNC manipulation undermine compatibilist accounts of the sort of control required for moral responsibility, they also undermine various agent-causal and non-agent-causal libertarian accounts as well. [source] Management strategies for plant invasions: manipulating productivity, disturbance, and competitionDIVERSITY AND DISTRIBUTIONS, Issue 3 2004Michael A. Huston ABSTRACT The traditional approach to understanding invasions has focused on properties of the invasive species and of the communities that are invaded. A well-established concept is that communities with higher species diversity should be more resistant to invaders. However, most recently published field data contradict this theory, finding instead that areas with high native plant diversity also have high exotic plant diversity. An alternative environment-based approach to understanding patterns of invasions assumes that native and exotic species respond similarly to environmental conditions, and thus predicts that they should have similar patterns of abundance and diversity. Establishment and growth of native and exotic species are predicted to vary in response to the interaction of plant growth rates with the frequency and intensity of mortality-causing disturbances. This theory distinguishes between the probability of establishment and the probability of dominance, predicting that establishment should be highest under unproductive and undisturbed conditions and also disturbed productive conditions. However, the probability of dominance by exotic species, and thus of potential negative impacts on diversity, is highest under productive conditions. The theory predicts that a change in disturbance regime can have opposite effects in environments with contrasting levels of productivity. Manipulation of productivity and disturbance provides opportunities for resource managers to influence the interactions among species, offering the potential to reduce or eliminate some types of invasive species. [source] Manipulation of self-assembly amyloid peptide nanotubes by dielectrophoresisELECTROPHORESIS, Issue 24 2008Jaime Castillo Abstract Self-assembled amyloid peptide nanotubes (SAPNT) were manipulated and immobilized using dielectrophoresis. Micro-patterned electrodes of Au were fabricated by photolithography and lifted off on a silicon dioxide layer. SAPNT were manipulated by adjusting the amplitude and frequency of the applied voltage. The immobilized SAPNT were evaluated by SEM and atomic force microscopy. The conductivity of the immobilized SAPNT was studied by I,V characterization, for both single SAPNT and bundles. This work illustrates a way to manipulate and integrate biological nanostructures into novel bio-nanoassemblies with concrete applications, such as field-effect transistors, microprobes, microarrays, and biosensing devices. [source] High-efficiency peptide analysis on monolithic multimode capillary columns: Pressure-assisted capillary electrochromatography/capillary electrophoresis coupled to UV and electrospray ionization-mass spectrometryELECTROPHORESIS, Issue 21 2003Alexander R. Ivanov Abstract High-efficiency peptide analysis using multimode pressure-assisted capillary electrochromatography/capillary electrophoresis (pCEC/pCE) monolithic polymeric columns and the separation of model peptide mixtures and protein digests by isocratic and gradient elution under an applied electric field with UV and electrospray ionization-mass spectrometry (ESI-MS) detection is demonstrated. Capillary multipurpose columns were prepared in silanized fused-silica capillaries of 50, 75, and 100 ,m inner diameters by thermally induced in situ copolymerization of methacrylic monomers in the presence of n -propanol and formamide as porogens and azobisisobutyronitrile as initiator. N -Ethylbutylamine was used to modify the chromatographic surface of the monolith from neutral to cationic. Monolithic columns were termed as multipurpose or multimode columns because they showed mixed modes of separation mechanisms under different conditions. Anion-exchange separation ability in the liquid chromatography (LC) mode can be determined by the cationic chromatographic surface of the monolith. At acidic pH and high voltage across the column, the monolithic stationary phase provided conditions for predominantly capillary electrophoretic migration of peptides. At basic pH and electric field across the column, enhanced chromatographic retention of peptides on monolithic capillary column made CEC mechanisms of migration responsible for separation. The role of pressure, ionic strength, pH, and organic content of the mobile phase on chromatographic performance was investigated. High efficiencies (exceeding 300,000 plates/m) of the monolithic columns for peptide separations are shown using volatile and nonvolatile, acidic and basic buffers. Good reproducibility and robustness of isocratic and gradient elution pressure-assisted CEC/CE separations were achieved for both UV and ESI-MS detection. Manipulation of the electric field and gradient conditions allowed high-throughput analysis of complex peptide mixtures. A simple design of sheathless electrospray emitter provided effective and robust low dead volume interfacing of monolithic multimode columns with ESI-MS. Gradient elution pressure-assisted mixed-mode separation CE/CEC-ESI-MS mass fingerprinting and data-dependent pCE/pCEC-ESI-MS/MS analysis of a bovine serum albumin (BSA) tryptic digest in less than 5 min yielding high sequence coverage (73%) demonstrated the potential of the method. [source] No Plastic Responses to Experimental Manipulation of Sperm Competition per se in a Free-Living FlatwormETHOLOGY, Issue 4 2010Peter Sandner In the absence of sperm competition evolutionary theory predicts low mating rates and low ejaculate expenditure per mating, and sex allocation theory for simultaneous hermaphrodites predicts a strongly female-biased sex allocation. In the presence of sperm competition a shift towards a more male-biased sex allocation and a higher ejaculate expenditure are predicted. The free-living flatworm Macrostomum lignano has been shown to respond plastically in mating rate, testis size, and sperm transfer to manipulation of the social group size, a proxy of the strength of sperm competition. However, manipulation of social group size may manipulate not only sperm competition, but also other factors, such as food supply and metabolite concentration. In this study we therefore manipulated sperm competition per se by repeatedly exposing individuals to partners that have either mated with rivals or not, while keeping the social group size constant. Our results suggest that M. lignano does not have the ability to detect sperm competition per se, as worms experimentally exposed to the presence or absence of sperm competition did not differ in sex allocation, sperm transfer or mating behavior. A response to our manipulation would have required individual recognition, the ability to detect self-referencing tags, or tags or traces left by rivals on or in the mating partners. We first discuss the possibility that highly efficient sperm displacement may have decreased the difference between the treatment groups and then propose three alternative cues that may allow M. lignano to respond plastically to the social group size manipulation used in earlier studies: assessment of the mating rate, chemical cues, or tactile cues. [source] Environmental Manipulation to Avoid a Unique Predator: Drinking Hole Excavation in the Agile Wallaby, Macropus agilisETHOLOGY, Issue 2 2007J. Sean Doody The simplest way of avoiding an ambush predator is to entirely avoid the habitat in which it hunts. However, this strategy requires that the prey species find alternative, risk-free sources of essential resources. Herein we describe a novel strategy used by agile wallabies (Macropus agilis) to avoid saltwater crocodile (Crocodylus porosus) predation: the creation of risk-free sites to obtain water. We studied the anti-predator behaviour of agile wallabies for 3 yr during the dry season along the Daly River, Northern Territory, Australia. Wallabies excavated holes in the sand 0.5,18.0 m from the water's edge, and preferred to drink from these holes over drinking from the river. We determined a hierarchy of preferred drinking-site options for the wallabies: non-river sites: springs, puddles, excavated holes; and river sites: sites with cover, shallow water sites and deep water sites. Drinking holes were twice as far from the water's edge in a river stretch with high crocodile density (2/km) than those in a stretch with low crocodile density (0.08/km). However, site differences could also be explained by river bank morphology. Collectively, our findings indicate that agile wallabies excavate drinking holes to avoid crocodile predation. We contend that this behaviour represents environmental manipulation specifically to alter the risk associated with obtaining a key resource. [source] Experimental Manipulation of Intraclutch Variation in the Great Reed Warbler Shows No Effect on Rejection of Parasitic EggsETHOLOGY, Issue 1 2003Zsolt Karcza In the continuing arms race between hosts and brood parasites, hosts are expected to reduce variation in the appearance of their own eggs within clutches, as it facilitates recognition of parasitic eggs. At the same time, by increasing interclutch variation, hosts should make it more difficult for parasites to evolve perfectly mimetic eggs. In this study, we experimentally manipulated intraclutch variation in the great reed warbler, Acrocephalus arundinaceus, in Hungary, where this species is heavily (c. 64%) parasitized by the common cuckoo, Cuculus canorus. We placed artificial cuckoo eggs, which appeared moderately mimetic to humans, in two groups of nests; in one group we increased variability of egg appearance within clutches by exchanging host eggs among nests. These clutches showed a significantly higher intraclutch variability than natural clutches, which we used as a control group. Our results indicate that it has no effect on rejection behaviour in this species, neither when variation was increased experimentally, nor within the natural range of variation displayed by our population. We suggest that when parasitism is high, selection for reduced intraclutch variation may be less important than frequency-dependent selection for increased variation between individuals within a host population. [source] A novel form of NF-,B is induced by Leishmania infection: Involvement in macrophage gene expressionEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 4 2008David Abstract Leishmania spp. are obligate intracellular parasites that inhabit the phagolysosomes of macrophages. Manipulation of host cell signaling pathways and gene expression by Leishmania is critical for Leishmania's survival and resultant pathology. Here, we show that infection of macrophages with Leishmania promastigotes in vitro causes specific cleavage of the NF-,B p65RelA subunit. Cleavage occurs in the cytoplasm and is dependent on the Leishmania protease gp63. The resulting fragment, p35RelA, migrates to the nucleus, where it binds DNA as a heterodimer with NF-,B p50. Importantly, induction of chemokine gene expression (MIP-2/CXCL2, MCP-1/CCL2, MIP-1,/CCL3, MIP-1,/CCL4) by Leishmania is NF-,B dependent, which implies that p35RelA/p50 dimers are able to activate transcription, despite the absence of a recognized transcriptional transactivation domain. NF-,B cleavage was observed following infection with a range of pathogenic species, including L.,donovani, L.,major, L.,mexicana, and L.,(Viannia) braziliensis, but not the non-pathogenic L.,tarentolae or treatment with IFN-,. These results indicate a novel mechanism by which a pathogen can subvert a macrophage's regulatory pathways to alter NF-,B activity. [source] Manipulation of NK cytotoxicity by the IAP family member LivinEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 12 2007Boaz Nachmias Abstract Natural killer (NK) cells are part of the innate immune system, capable of killing tumor and virally infected cells. NK cells induce apoptosis in the target cell by either granule- or receptor-mediated pathways. A set of inhibitory and activation ligands governs NK cell activation. As transformed cells often attempt to evade NK cell killing, up-regulation of a potential anti-apoptotic factor should provide a survival advantage. The inhibitor of apoptosis protein (IAP) family can inhibit apoptosis induced by a variety of stimuli. We have previously described a new IAP family member, termed Livin, which has two splice variants (, and ,) with differential anti-apoptotic activities. In this study, we explore the ability of Livin to inhibit NK cell-induced killing. We demonstrate that Livin,, moderately protects against NK cell killing whereas Livin,, augments killing. We show that Livin,, inhibition in Jurkat cells is apparent upon concomitant activation of an inhibitory signal, suggesting that Livin augments an extrinsic inhibitory signal rather than functioning as an independent inhibitory mechanism. Finally, we demonstrate that detection of both Livin isoforms in melanoma cells correlates with a low killing rate. To date, this is the first evidence that directly demonstrates the ability of IAP to protect against NK cell-induced apoptosis. [source] Novel polyketides synthesized with a higher plant stilbene synthaseFEBS JOURNAL, Issue 13 2001Hiroyuki Morita The physiological function of the stilbene synthase (STS) from groundnut (Arachis hypogaea) is the formation of resveratrol. The enzyme uses 4-coumaroyl-CoA, performs three condensations with malonyl-CoA, and folds the resulting tetraketide into a new aromatic ring system. We investigated the capacity for building novel and unusual polyketides from alternative substrates. Three types of products were obtained: (a) complete reaction (stilbene-type), (b) three condensations without formation of an aromatic ring (CTAL-type pyrone derailment), and (c) two condensations (BNY-type pyrone derailment). All product types were obtained from 4-fluorocinnamoyl-CoA and analogs in which the coumaroyl moiety was replaced by furan or thiophene. Only type (b) and (c) products were synthesized from other 4-substituted 4-coumaroyl-CoA analogs (-Cl, -Br, -OCH3). Benzoyl-CoA, phenylacetyl-CoA, and medium chain aliphatic CoA esters were poor substrates, and the majority of the products were of type (c). The results show that minor modifications can be used to direct the enzyme reaction to form a variety of different and new products. Manipulation of the biosynthesis of polyketides by synthetic analogs could lead to the development of a chemical library of pharmaceutically interesting novel polyketides. [source] Liquid-Crystal Polymers: Liquid-Crystalline Polymer with a Block Mesogenic Side Group: Photoinduced Manipulation of Nanophase-Separated Structures (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 23 2009Mater. The inside cover image represents a novel azobenzene liquid-crystalline (LC) polymer with a block mesogenic side group, which exhibits a lamellar structure after annealing in an LC phase. Whereas irradiation with linearly polarized light aligns the lamellae parallel to the polarization, irradiation with unpolarized light erases the surface morphology accompanied by photochemical phase transition, as reported by K. Okano et al. on page 3804. [source] Liquid-Crystalline Polymer with a Block Mesogenic Side Group: Photoinduced Manipulation of Nanophase-Separated StructuresADVANCED FUNCTIONAL MATERIALS, Issue 23 2009Kunihiko Okano Abstract In this report, a novel type of photoresponsive liquid crystalline polymer with a block mesogenic side-group is demonstrated. The block mesogene is an amphipathic molecule containing a hydrophobic mesogene (azotolane moiety) and hydrophilic oligooxyethylene moieties in the same unit. The block mesogene in the polymer plays a role in liquid crystalline, amphiphilic and photoresponsive properties. As expected, a film prepared from the polymer exhibits phase separation of a lamellar structure due to cooperative motion between liquid crystal assembly and nanophase separation. The morphology of the lamellae can be aligned upon irradiation of linearly polarized light. Moreover, a photochemical phase transition induced by unpolarized UV irradiation erases the surface morphology. The erased nanostructure can be recovered by annealing or irradiation of linearly polarized light, meaning that the surface morphology is rewritable via a photochemical process. [source] Manipulation of flooding and arbuscular mycorrhiza formation influences growth and nutrition of two semiaquatic grass speciesFUNCTIONAL ECOLOGY, Issue 6 2000S. P. Miller Abstract 1Two semiaquatic grasses, Panicum hemitomon Schultes and Leersia hexandra Schwartz, were grown for 12 weeks in sterilized soil in experimental mesocosms, with and without the addition of arbuscular mycorrhizal (AM) fungal inoculum (as nonsterilized soil), under the following rooting-zone flood regimes: waterlogged (W), free-draining (D), beginning W and ending D (W,D), and beginning D and ending W (D,W). The purpose of the experiment was to determine whether these controlled water regimes affected both colonization of wetland grasses by AM fungi and the effects of the colonization on various plant parameters. 2Water regime, addition of inoculum, and their interaction were highly significant effects on total and proportion of root length colonized by AM fungi. Trends were very similar for the two grass species. Colonization was less and plants smaller in the W and W,D than in the D and D,W treatments. The viability of mycorrhiza at the end of the experiment, as measured by vital staining techniques, was not affected by changes in water level. 3Colonized plants in all water level treatments showed an improvement in phosphorus (P) nutrition over noncolonized plants. Colonized grasses of both species gained consistently more P per plant and had greater tissue P concentrations, with the greatest P concentration in the most heavily colonized plants (from the D and D,W treatments). 4The effect of flooding on the mycorrhizal association depended largely on the extent to which the association was already established when the flooding occurred. Flooding reduced the initiation of colonization either directly or indirectly, but once the fungi were established in the roots they were able to maintain and expand with the growing root system. [source] Functionalized Siloles: Versatile Synthesis, Aggregation-Induced Emission, and Sensory and Device ApplicationsADVANCED FUNCTIONAL MATERIALS, Issue 6 2009Zhen Li Abstract The synthesis of functionalized siloles has been a challenge because of the incompatibility of polar functional groups with the reactive intermediates in the conventional protocols for silole synthesis. In this work, a synthetic route for silole functionalization is elaborated, through which a series of functionalized siloles are successfully prepared. Whereas light emissions of traditional luminophores are often quenched by aggregation, most of the functionalized siloles show an exactly opposite phenomenon of aggregation-induced emission (AIE). The siloles are nonemissive when dissolved in their good solvents but become highly luminescent when aggregated in their poor solvents or in the solid state. Manipulation of the aggregation,deaggregation processes of the siloles enables them to play two seemly antagonistic roles and work as both excellent quenchers and efficient emitters. The AIE effect endows the siloles with multifaceted functionalities, including fluorescence quenching, pH sensing, explosive detection, and biological probing. The sensing processes are very sensitive (with detection limit down to 0.1,ppm) and highly selective (with capability of discriminating among different kinds of ions, explosives, proteins, DNAs, and RNAs). The siloles also serve as active layers in the fabrication of electroluminescent devices and as photosensitive films in the generation of fluorescence patterns. [source] Manipulation of herbage production by altering the pattern of applying nitrogen fertilizerGRASS & FORAGE SCIENCE, Issue 1 2008D. Hennessy Abstract The redistribution of herbage production during the growing season to synchronize herbage supply with feed demand by livestock by altering the application pattern of a range of nitrogen (N) fertilizer rates was studied. Application rates of N were 50, 150 and 250 kg N ha,1 per annum and patterns were with 0·60 of N fertilizer applied before June (treatment RN) and with only 0·20 of N fertilizer before June (treatment IN). Treatments were imposed in a cutting (simulated grazing) experiment (Experiment 1), which was conducted for 2 years and a grazing experiment (Experiment 2) which was conducted for 3 years. In both experiments, herbage production was reduced in April and May and increased in the June,October period on treatment IN relative to RN, but annual herbage production was not significantly affected except in the third year of Experiment 2, when treatment RN had significantly (P < 0·05) higher herbage production than treatment IN. Crude protein (CP) concentration of herbage was lower in April and May on treatment IN than treatment RN. However, CP concentration of herbage was rarely below 150 g kg,1 DM and so it is unlikely that livestock productivity would be compromised. On treatment IN, concentrations of CP in herbage were higher in the late summer than on treatment RN, which may increase livestock productivity during July and August when livestock productivity is often lower. Altering the strategy of application of N fertilizer did not affect in vitro dry matter digestibility of herbage. [source] Magnetic Liquid Marbles: Manipulation of Liquid Droplets Using Highly Hydrophobic Fe3O4 NanoparticlesADVANCED MATERIALS, Issue 6 2010Yan Zhao Magnetic liquid marbles exhibit a remarkable ability to be opened (see image) and closed reversibly under the action of a magnetic field. Liquid can be either extracted from or added to the opened liquid marble simply with a capillary needle. Two opened liquid marbles can also be coalesced into a larger one. The magnetic liquid marbles can be maneuvered two- and three-dimensionally. [source] Tunable Hydrogels for External Manipulation of Cellular Microenvironments through Controlled PhotodegradationADVANCED MATERIALS, Issue 1 2010April M. Kloxin A photocleavable, poly(ethylene-glycol)-based hydrogel is presented in which predictable, user-defined gradients in the network's structure can be fabricated in real time under cytocompatible conditions. This platform provides new opportunities to investigate how material structure influences cell function. Here, cell morphology is directed spatially by degradation-induced gradients in the local polymer density (see figure, scale bars: 50 ,m). [source] Recent Progress in Polymer Solar Cells: Manipulation of Polymer:Fullerene Morphology and the Formation of Efficient Inverted Polymer Solar CellsADVANCED MATERIALS, Issue 14-15 2009Li-Min Chen Abstract Polymer morphology has proven to be extremely important in determining the optoelectronic properties in polymer-based devices. The understanding and manipulation of polymer morphology has been the focus of electronic and optoelectronic polymer-device research. In this article, recent advances in the understanding and controlling of polymer morphology are reviewed with respect to the solvent selection and various annealing processes. We also review the mixed-solvent effects on the dynamics of film evolution in selected polymer-blend systems, which facilitate the formation of optimal percolation paths and therefore provide a simple approach to improve photovoltaic performance. Recently, the occurrence of vertical phase separation has been found in some polymer:fullerene bulk heterojunctions.1,3 The origin and applications of this inhomogeneous distribution of the polymer donor and fullerene acceptor are addressed. The current status and device physics of the inverted structure solar cells is also reviewed, including the advantage of utilizing the spontaneous vertical phase separation, which provides a promising alternative to the conventional structure for obtaining higher device performance. [source] Manipulation of Individual Carbon Nanotubes by Reconstructing the Intracellular Transport of a Living CellADVANCED MATERIALS, Issue 10-11 2009Cerasela Zoica Dinu We used kinesin motor protein and its microtubule track to transport multi-walled carbon nanotubes (MWNTs) on engineered surfaces. Using a flow chamber, surface-adsorbed kinesins are shown to transport red-labeled microtubules loaded with green cargos of MWNTs. Our results establish a platform for assembling individually addressable MWNT nanostructures using microtubule templates. [source] Bottom,Up Fabrication of Carbon-Rich Silicon Carbide Nanowires by Manipulation of Nanometer-Sized Ethanol Menisci,ADVANCED MATERIALS, Issue 12 2005M. Tello A nanometer-sized ethyl alcohol meniscus induced between a conductive atomic force microscope tip and a silicon surface (see Figure) allows the fabrication of nanodots or nanowires of SiCx at a predetermined position on the substrate. The meniscus size and kinetic parameters control the nanostructure size. [source] Membrane Photolithography: Direct Micropatterning and Manipulation of Fluid Phospholipid Membranes in the Aqueous Phase Using Deep-UV Light,ADVANCED MATERIALS, Issue 14 2004K. Yee A wet photolithography approach using light-activated, localized, oxidative chemistry can directly pattern fluid phospholipid bilayers submerged in aqueous phases. Targeted incorporation of secondary components within pattern voids (see Figure) allows many membrane dynamical processes to be probed and optically defined arrays of holes, functional membrane microdomains, and proteins embedded in a lipidic background can be designed. [source] Scanning Probe Studies of Porphyrin Assemblies and Their Supramolecular Manipulation at a Solid,Liquid InterfaceADVANCED MATERIALS, Issue 24 2003J.A.A.W. Elemans Dynamic self-assembly and metal,ligand coordination processes of porphyrin hexamers on a solid,liquid interface have been visualized with scanning tunneling microscopy. The organization of these hexamers into stable and highly organized arrays of "edge-on" or "face-on" oriented molecules can be controlled by the addition of different ditopic axial ligands (see Figure). [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||