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Direct Observation (direct + observation)
Selected AbstractsDirect Observation of Inversion Domain Boundaries of GaN on c -Sapphire at Sub-ångstrom Resolution,ADVANCED MATERIALS, Issue 11 2008Fude Liu Inversion domain boundaries (IDBs) of GaN are studied by a high-resolution technique. The IDB separates adjacent domains of opposite polarity. The image shows a GaN IDB in the [bar;2110] projection. The theoretical IDB structure fits the experimentally obtained structure well. The inset is an image acquired from a very thin region on the right side of the IDB. It can indicate the polarity of GaN directly. [source] Direct Observation of Multilayer Adsorption on Alumina Grain BoundariesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2007Shen J. Dillon Grain-boundary films 0.6 nm in size have been observed on the grain boundaries of neodymia (Nd2O3)-doped alumina (,-Al2O3) sintered at 1800°C. Direct observation by high-angle annular dark-field imaging in the aberration-corrected scanning transmission electron microscope shows that this type of grain-boundary structure is the result of multilayer adsorption. Neodymium cations adsorb onto the faces of each of the two grains that comprise the grain boundary by substituting for aluminum cations. The positions of these cations are slightly distorted relative to the perfect lattice, and a third atomic layer in the core of the grain-boundary resides between these two layers. The measurements also confirm that the thickness deduced from high-resolution transmission electron microscopy lattice images are accurate. [source] Direct Observation of , -Chloro- p -quinodimethane as the Real Monomer in the Gilch Polymerization Leading to Poly(p -phenylene vinylene)sMACROMOLECULAR RAPID COMMUNICATIONS, Issue 2 2007Jens Wiesecke Abstract It is the general consensus that in Gilch polymerizations the 1,4-bis(chloromethylene)benzene starting material first changes into p -quinodimethane intermediates which then act as the real monomers. However, direct observation of these intermediates has not been possible so far. This is because usually the p -quinodimethane auto-initiates its rapid radical polymerization instantaneously, keeping its concentration extremely low throughout the whole process. Here it is shown that, when the reaction is carried out at very low temperatures, the formation of p -quinodimethane still proceeds but chain growth is suppressed. Hence, the concentration of the active monomer reaches a level sufficient for NMR analysis. [source] Practitioner Review: The Role of Direct Observation in the Assessment of Young ChildrenTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 7 2001A. D. Pellegrini In this review I examine the role of play and assessment in the lives of young children. These two seemingly opposing constructs are first defined. Next, I address a particularly important form of assessment, "high stakes" assessment, and argue that if it must be used, we should use a variety of assessment methods. One such method that I discuss in great detail is the use of direct observations of children's play. Examples of reliable and valid inferences about children's social cognitive functioning made with this family of methods are provided. Two specific observational instruments (one for observing play in the classroom and one for observing play in the playground) are presented. Recommendations for their use by practitioners are made. [source] Fluorescent Cyclic Voltammetry of Immobilized Azurin: Direct Observation of Thermodynamic and Kinetic Heterogeneity,ANGEWANDTE CHEMIE, Issue 33 2010Jante Schwankungen im formalen elektrochemischen Potential (E0) und in der Elektronentransfergeschwindigkeit (k0) des blauen Kupferproteins Azurin wurden direkt beobachtet. Die Fluoreszenz-Cyclovoltammetrie wurde als ein neues Verfahren angewendet, um die Eigenschaften von 100,1000,Proteinen zu charakterisieren. Dabei wurden starke Schwankungen für E0 und k0 bestimmt, und man konnte unterschiedliche Arten von Heterogenitäten unterscheiden. [source] Innentitelbild: Direct Observation of Contact Ion-Pair Formation in Aqueous Solution (Angew. Chem.ANGEWANDTE CHEMIE, Issue 33 200933/2009) Der Kontakt zwischen Anionen und Kationen in wässriger Lösung ist direkten spektroskopischen Methoden schwer zugänglich. Das Cs8[Nb6O19]-Polyoxometallatsalz mit hoher negativer Ladung, sphärischer Symmetrie, exzellentem Röntgenstreuvermögen und sehr guter Wasserlöslichkeit bietet ein ideales Szenario. Auf S.,6252,ff. schildern M.,R. Antonio, M. Nyman und T.,M. Anderson anhand von SAXS-Experimenten (Kleinwinkelröntgenstreuung), wie die Bildung von Kontaktionenpaaren in Lösung der Situation im Festkörper exakt gleicht. [source] Direct Observation of Contact Ion-Pair Formation in Aqueous Solution,ANGEWANDTE CHEMIE, Issue 33 2009Nackt oder neutralisiert? SAXS-Messungen (SAXS: Kleinwinkelröntgenstreuung) liefern direkte Informationen über die Bildung der Kontaktionenpaare zwischen dem [Nb6O19]8, -Polyoxometallat und den acht Ladungen ausgleichenden Caesium-Kationen in wässriger Lösung. Die Gyrationsradien (Rg) für Cs8[Nb6O19] und [Nb6O19]8, sind gezeigt. [source] Direct Observation of Residents in the Emergency Department: A Structured Educational ProgramACADEMIC EMERGENCY MEDICINE, Issue 4 2009Michele L. Dorfsman MD Abstract Objectives:, The objective was to describe the implementation of a program of structured direct observation of emergency medicine (EM) residents during clinical shifts in the emergency department (ED). Methods:, The authors developed a program in which an observer spent 4 to 5 hours with each resident, without intervening in the clinical encounters. A structured data form was developed to document the resident's performance in a number of defined clinical areas relevant to patient care and mastery of the core competencies. Individual strengths and weaknesses were noted, and the observer provided directed feedback at the end of the session. Results:, Over an 18-month period, 32 EM residents were observed during their ED shifts. The sessions not only provided specific information on individual residents' performances, but also identified areas where the residency program curriculum could be enhanced and provided a means of assessing mastery of the core competencies. In addition, the program provided an opportunity to give detailed and timely directed feedback to residents. Both residents and attending staff found the sessions acceptable and useful. Conclusions:, Implementation of a structured direct observation program was feasible and well received and provided insight into the strengths and weaknesses of residents both individually and as a group. [source] Direct Observation of Anion-Mediated Translocation of Fluorescent Oligoarginine Carriers into and across Bulk Liquid and Anionic Bilayer MembranesCHEMBIOCHEM, Issue 1 2005Naomi Sakai Dr. Abstract The recent hypothesis that counteranion-mediated dynamic inversion of charge and solubility might contribute to diverse functions of oligoarginines in biomembranes was tested with two fluorescently labelled oligomers, FL-R8, one of the most active cell-penetrating peptides, and its longer version, FL-R16. We report evidence for counteranion-mediated phase transfer from water into bulk chloroform and anionic lipid-bilayer membranes as well as reverse-phase transfer from bulk chloroform and across intact lipid-bilayer membranes into water. The differences found between FL-R8 and FL-R16 with regard to location in the bilayer and reverse-phase transfer from bulk and lipid-bilayer membranes into water implied that the reported results may be relevant for biological function. [source] First Direct Observation of the Higher Triplet Excited States of Substituted Oligothiophenes by Two-Color Two-Laser Flash PhotolysisCHEMPHYSCHEM, Issue 8 2004Mamoru Fujitsuka Prof. Dr. The higher triplet excited states (Tn) of oligothiophenes [trimer (3T), tetramer (4T), and pentamer (5T)] were directly observed for the first time during two-color two-laser flash photolysis employing a picosecond laser. The lifetimes of the Tn states of the oligomers were a few tens of picoseconds. The internal conversion between T2,T1 is the rate-determining step for the oligothiophenes (see picture). [source] Using Buyer,Supplier Performance Frontiers to Manage Relationship Performance,DECISION SCIENCES, Issue 1 2009Anthony D. Ross ABSTRACT This article presents a consensus-building methodology to implement dyadic performance measurement. It focuses on transmuting supplier performance and buyer performance metrics on several important attributes into actionable relationship management plans using Clark's (1996) theory of performance frontiers. Access to the supplier performance management program of a Fortune 100 corporation was granted to the research team. Direct observation of practice and in-depth discussions with several managers provided a roadmap for investigating both the literature on quantitative evaluation methods and the empirically derived theory on buyer,supplier relationships from several perspectives. This study describes a multiphase, iterative framework that uses current methods and theory on dyadic buyer,supplier evaluation to consider: (i) evaluation criteria and their importance; (ii) whether the improvement focus should be on strengths, weaknesses, or both; and (iii) whether the referent role supplier should be the ideal supplier, best supplier, or best-in-strategic-group supplier in the focal supply base. We illustrate a unifying approach by reporting results from a large buyer and 35 of its key suppliers. This research makes the case for managing supplier relationships through the dyadic performance lens. The outputs from this framework provide individual supplier improvement paths which are actionable prescriptions for each buyer,supplier dyad, as well as recommendations for strategic group formation. [source] Direct observation of frost wedging in alpine bedrockEARTH SURFACE PROCESSES AND LANDFORMS, Issue 6 2001Norikazu Matsuoka Abstract Width and temperature of rock joints were automatically monitored in the Japanese Alps. Three years of monitoring on a sandstone rock face shows two seasonal peaks of joint widening in autumn and spring. The autumn events are associated with short-term freeze,thaw cycles, and the magnitude of widening reflects the freezing intensity and water availability. The short-term freezing can produce wedging to a depth of at least 20,cm. The spring events follow a rise in the rock surface temperature to 0,°C beneath the seasonal snowcover, and likely originate from refreezing of meltwater entering the joint. Some of these events contribute to permanent enlargement of the joint. Two other joints on nearby rock faces experience only sporadic widening accompanying freeze,thaw cycles and insignificant permanent enlargement. Observations indicate that no single thermal criterion can explain frost weathering. The temperature range at which wedging occurs varies with the bedrock conditions, water availability and duration of freezing. Copyright © 2001 John Wiley & Sons, Ltd. [source] Prostate cancer in London: is the triadic clinical encounter the standard?INTERNATIONAL JOURNAL OF UROLOGICAL NURSING, Issue 2 2008Amanda Euesden Hughes Abstract It has been reported that men with prostate cancer in London were less satisfied with the service they received than patients with other cancers. Studies from the USA have looked at the experience of the prostate cancer couple. It has been established that the cancer couple have information needs and that when a clinical encounter is triadic in nature, these needs are more likely to be met and information is more likely to be retained. The aim of this study was to examine the clinic attendance patterns of men in London with prostate cancer (n = 200). A comparison group of women in London with breast cancer was identified (n = 200). Direct observation of the groups was performed, accompanied/unaccompanied (triadic/dyadic) attendance was recorded and demographic data were extracted from the clinical notes. Forty-one percent (81) of the women experienced their clinical encounter as a triad compared with 24% (48) of the prostate group who experienced their clinical encounter as a dyad between themselves and their health care provider (p < 0.05). In the first year of diagnosis, men with prostate cancer were more likely to experience a triadic encounter, but this was more evenly distributed throughout the cancer journey for women with breast cancer. There did not appear to be a correlation with marriage and triadic encounters for either group. Men with prostate cancer in this tertiary referral centre in London are less likely to experience a triadic clinical encounter than women with breast cancer. Further work is needed to establish a relationship between unmet informational needs of the prostate cancer couple and the high level of dissatisfaction in the prostate cancer population in London, but the nature of the dyadic encounter may play a part in this. [source] Season-long mating disruption of citrus leafminer, Phyllocnistis citrella Stainton, with an emulsified wax formulation of pheromoneJOURNAL OF APPLIED ENTOMOLOGY, Issue 6 2010L. L. Stelinski Abstract The citrus leafminer, Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), is a major worldwide pest of citrus. Larval feeding by this insect facilitates proliferation of citrus bacterial canker, Xanthomonas axonopodis pv. citri. Herein, we describe a season-long disruption trial of P. citrella with a newly developed, emulsified wax dispenser of pheromone (SPLAT-CLMTM). A formulation containing a 3 : 1 blend of (Z,Z,E)-7,11,13-hexadecatrienal:(Z,Z)-7,11-hexadecadienal at a 0.2% loading rate of active ingredient by weight and deployed twice per season (24 weeks total) at 490 g of formulation/ha caused season-long disruption of male moth catch in pheromone traps as well as reduced leaf infestation. Analysis of pheromone release from dispensers by gas chromatography revealed that effective disruption of P. citrella occurred at a deployment rate of 126 ,g of (Z,Z,E)-7,11,13-hexadecatrienal/ha/h. Direct observation of moth behaviour in the field suggested that disruption by this formulation occurred by a non-competitive mechanism. A formulation of the 3 : 1 attractive blend at a 0.02% pheromone loading rate caused only 2,6 weeks of disruption per deployment and did not reduce leaf infestation during mid and end of the season evaluations. A formulation containing 0.2% of (Z,Z)-7,11-hexadecadienal alone and deployed at 490 g/ha caused 6,7 weeks of moth disruption to pheromone traps and did not prevent leaf infestation, while an identical formulation loaded with 0.02% (w/w) of (Z,Z)-7,11-hexadecadienal alone had no effect on P. citrella orientation to pheromone traps. The SPLAT formulation evaluated herein appears to be an excellent release device for (Z,Z,E)-7,11,13-hexadecatrienal given that approximately 100 days of steady release occurred following an initial brief (ca. 7 days) burst of higher release. The advantages of SPLAT as a formulation for P. citrella disruption include low cost of manufacturing, biodegradable and weather resistant characteristics, and flowability allowing machine application. Mating disruption should be an effective alternative to insecticides for management of P. citrella and may reduce the incidence of citrus canker. [source] The Cost-Effectiveness of Supported Employment for People with Severe Intellectual Disabilities and High Support Needs: a Pilot StudyJOURNAL OF APPLIED RESEARCH IN INTELLECTUAL DISABILITIES, Issue 1 2000Julia Shearn The costs and outcomes of supporting seven people with severe intellectual disabilities and high support needs in part-time employment were compared with those of a Special Needs Unit (SNU) of a day centre, both within-subject and against an equal-sized comparison group. The income of those employed was described. Direct observation of the employment activities and representative SNU activities were undertaken to assess participant engagement in activity and receipt of assistance, social contact in general and social contact from people other than paid staff. Costs of providing service support were calculated taking account of staff : service user ratios, staff identities and wage rates and service-administrative and management overheads. Employment was associated with greater receipt of assistance, higher task-related engagement in activity and more social contact from people other than paid staff. SNU activities were associated with greater receipt of social contact. Supporting people in employment was more expensive than in the SNU. Cost-effectiveness ratios of producing assistance and engagement in activities were equivalent across the comparative contexts. The SNU was more cost-effective in producing social involvement; employment in producing social contact from people other than paid staff. [source] Direct Observation of Multilayer Adsorption on Alumina Grain BoundariesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2007Shen J. Dillon Grain-boundary films 0.6 nm in size have been observed on the grain boundaries of neodymia (Nd2O3)-doped alumina (,-Al2O3) sintered at 1800°C. Direct observation by high-angle annular dark-field imaging in the aberration-corrected scanning transmission electron microscope shows that this type of grain-boundary structure is the result of multilayer adsorption. Neodymium cations adsorb onto the faces of each of the two grains that comprise the grain boundary by substituting for aluminum cations. The positions of these cations are slightly distorted relative to the perfect lattice, and a third atomic layer in the core of the grain-boundary resides between these two layers. The measurements also confirm that the thickness deduced from high-resolution transmission electron microscopy lattice images are accurate. [source] Direct observation of the unstable intermediates in radical addition reaction by using an interfacing microchip combined with an NMRMAGNETIC RESONANCE IN CHEMISTRY, Issue 11 2007Masamichi Nakakoshi Abstract Direct observation of the unstable intermediate in the radical addition reaction of the oxime ether 1 mediated by triethylborane (Et3B) is described using 1H and 11B micro channeled cell for synthesis monitoring (MICCS), which was recently developed as an interfacing microchip for NMR. It was possible that the signal of the intermediate was observed as a result of using MICCS technique with a standard NMR instrument. This result supports the structure of the intermediate analyzed by diffusion-ordered spectroscopy (DOSY) NMR method in a previous paper. The procedure of micro channeled cell for synthesis monitoring-nuclear magnetic resonance (MICCS-NMR) was much easier than that of DOSY method. It was proven that it could be applied to the reaction in an anhydrous condition. Copyright © 2007 John Wiley & Sons, Ltd. [source] In vivo31P MRS detection of an alkaline inorganic phosphate pool with short T1 in human resting skeletal muscleNMR IN BIOMEDICINE, Issue 8 2010H. E. Kan Abstract Non-invasive determination of mitochondrial content is an important objective in clinical and sports medicine. 31P MRS approaches to obtain information on this parameter at low field strength typically require in-magnet exercise. Direct observation of the intra-mitochondrial inorganic phosphate (Pi) pool in resting muscle would constitute an alternative, simpler method. In this study, we exploited the higher spectral resolution and signal-to-noise at 7T to investigate the MR visibility of this metabolite pool. 31P in vivo MR spectra of the resting soleus (SOL) muscle were obtained with 1H MR image-guided surface coil localization (six volunteers) and of the SOL and tibialis anterior (TA) muscle using 2D CSI (five volunteers). A resonance at a frequency 0.38,ppm downfield from the cytosolic Pi resonance (Pi1; pH 7.0,±,0.04) was reproducibly detected in the SOL muscle in all subjects and conditionally attributed to the intra-mitochondrial Pi pool (Pi2; pH 7.3,±,0.07). In the SOL muscle, the Pi2/Pi1 ratio was 1.6 times higher compared to the TA muscle in the same individual. Localized 3D CSI results showed that the Pi2 peak was present in voxels well away from blood vessels. Determination of the T1 of the two Pi pools in a single individual using adiabatic excitation of the spectral region around 5,ppm yielded estimates of 4.3,±,0.4 s vs 1.4,±,0.5 s for Pi1 and Pi2, respectively. Together, these results suggest that the intra-mitochondrial Pi pool in resting human skeletal muscle may be visible with 31P MRS at high field. Copyright © 2010 John Wiley & Sons, Ltd. [source] Direct observation of Landau damping in a solid state plasmaPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 1 2008M. P. Hasselbeck Abstract We use ultrafast THz spectroscopy to study Landau damping in a coherent plasma system. A series of InSb-based bulk heterostructures provide increasing spatial confinement that restricts the scattering wave vector in the electron-electron interaction. This results in a dramatic reduction of the plasma contribution to the radiation signal. The experimental results are explained by model calculations. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Direct observation of hillocks on pendeo-epitaxial GaN films and stabilization of GaN seed layers for hillock-free surfacePHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2003H. S. Cheong Abstract Hillocks formed on pendeo-epitaxial GaN (PE-GaN) films grown by metalorganic chemical vapor deposition were observed by scanning electron microscopy, atomic force microscopy and high-resolution transmission electron microscopy. In order to suppress hillock formation on PE-GaN films, a two-step growth technique was employed. In the first-step growth, whose growth temperature and V/III ratio were relatively low, it was necessary to suppress hillock formation on the surface, and reduce the crystallographic tilt in the wing regions of PE-GaN films. In the second-step growth, whose growth temperature and V/III ratio were relatively high, complete coalescence without tilt in the wing regions was achieved by a high lateral growth rate. [source] Ergonomic exposure case studies in Massachusetts fishing vesselsAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue S2 2002Scott Fulmer MS Abstract Background Musculoskeletal disorders may not have been studied as much as greater risks in the dangerous environment of commercial fishing. Primary prevention of risk for these kinds of injuries and illnesses begins by a detailed understanding of what risks are likely to be common in the different fisheries, and how those risks might be reduced. Methods Ergonomic job analyses were conducted on three different types of fishing vessels in Massachusetts: gillnetting, otter trawling, and lobstering. Direct observation was used to link posture to task. Noise measurements, tool analysis, and cycle time measurements were also included. Results Production speed, materials handling, and vessel movement contributed to musculoskeletal stress by affecting observable postural deviation, repetition, and forceful exertions. Conclusions Interventions to reduce ergonomic risk factors might be possible through utilization of below deck space in certain boats, through better technology, or through simple tool adjustments. Am. J. Ind. Med. Suppl. 2:10,18, 2002. © 2002 Wiley-Liss, Inc. [source] The use of generalizability theory to estimate data reliability in single-subject observational researchPSYCHOLOGY IN THE SCHOOLS, Issue 5 2007Pui-Wa Lei Direct observation of behaviors is a data collection method customarily used in clinical and educational settings. Repeated measures and small samples are inherent characteristics of observational studies that pose challenges to the numerical estimation of reliability for observational data. In this article, we review some debates about the use of Generalizability Theory in estimating reliability of single-subject observational data. We propose that it could be used but under a clearly stated set of conditions. The conceptualization of facets and object of measurement for a common design of observational research is elucidated under a different light. We provide two numerical examples to illustrate the ideas. Limitations of using Generalizability Theory to estimate reliability of observational data are discussed. © 2007 Wiley Periodicals, Inc. Psychol Schs 44: 433,439, 2007. [source] Direct observation of deuterium migration in crystalline-state reaction by single-crystal neutron diffraction.ACTA CRYSTALLOGRAPHICA SECTION B, Issue 4 2001The H atoms bonded to the chiral C atoms (stereogenic center) of the 1-cyanoethyl groups in two cobalt complexes, [(R)-1-cyanoethyl]bis(dimethylglyoximato)(pyridine)cobalt(III) (2) and [(R,S)-1-cyanoethyl]bis(dimethylglyoximato)(piperidine)cobalt(III) (3), were replaced with D atoms, such as Co,C*D(CH3)CN. The crystals of the two cobalt complexes were irradiated with a xenon lamp for 72,h and 27,d, respectively. The unit-cell dimensions were gradually changed with retention of the single-crystal form. The crystal structures after irradiation were determined by neutron diffraction. In each crystal the chiral 1-cyanoethyl group of one of the two crystallographically independent molecules was partly inverted to the opposite configuration, whereas that of the other molecule kept the original configuration. The C*,D bond in the inverted group was completely conserved in the process of the inversion of the chiral alkyl group. This suggests that the inversion of the chiral 1-cyanoethyl group proceeds with the rotation of the cyanoethyl radical after the Co,C bond cleavage by photo-irradiation so that the opposite side of the radical faces the Co atom. This is followed by recombination of the Co,C bond to form the inverted 1-cyanoethyl group. [source] Methods: Measuring physical activity in public open space , an electronic device versus direct observationAUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 1 2002Andrew J. Milat Objective: To evaluate the practicality and validity of using infra-red beam counters (IRBCs) to measure walking path use and overall park use. Method: Direct observation was carried out simultaneously with IRBC data collection in five parks on seven non-consecutive days during February-March in 1998 and on matched days in 1999. A second validation study was undertaken in one park in October 1999. Results: The IRBC over-estimated the observed number of people using walking paths by 14% to 78%. When assessed by path volume, the difference between the IRBC and observer ranged from 10% under-estimation to 16% over-estimation. In a more rigorous evaluation of path volume the IRBC under-estimated the observed count by 20%. The extent to which the IRBC equated with the number of observed park users varied from 69% underestimation to no difference. Conclusion: IRBCs are not appropriate for measuring the number of people engaging in physical activity in parks. Implications: IRBCs cannot replace direct observation for the collection of valid data on physical activity participation in parks. Further research is needed to determine settings in which electronic devices such as IRBCs may provide valid data on physical activity participation. [source] Methodological considerations when conducting direct observation in an outdoor environment: our experience in local parksAUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 2 2001Susanne Engelhard Objective: This paper discusses some of the inherent methodological limitations of gathering data via direct observation using local parks as a case study. Methods: Direct observation was carried out in five parks on seven non-consecutive days in 1998 and on matched days in 1999. Information recorded for each person included the time of park entry and exit, gender, age group, and activity/ies undertaken while in the park. Methodological considerations: The location of the observation point, observer reliability, recording and accuracy of data, and specific issues related to outdoor observation areas should all be considered when designing a study incorporating direct observation as a data collection method. Conclusions: Direct observation can provide valuable information. However, pilot testing is essential for minimising potential problems associated with this method and optimising data quality. Implications: The issues discussed in this paper provide a useful guide for other researchers undertaking direct observation in outdoor environments. [source] Thermally Responsive Supramolecular Nanomeshes for On/Off Switching of the Rotary Motion of F1 -ATPase at the Single-Molecule LevelCHEMISTRY - A EUROPEAN JOURNAL, Issue 6 2008Satoshi Yamaguchi Dr. Abstract The artificial regulation of protein functions is essential for the realization of protein-based soft devices, because of their unique functions conducted within a nano-sized molecular space. We report that self-assembled nanomeshes comprising heat-responsive supramolecular hydrogel fibers can control the rotary motion of an enzyme-based biomotor (F1 -ATPase) in an on/off manner at the single-molecule level. Direct observation of the interaction of the supramolecular fibers with a microbead unit tethered to the F1 -ATPase and the clear threshold in the size of the bead required to stop ATPase rotation indicates that the bead was physically blocked so as to stop the rotary motion of ATPase. The temperature-induced formation and collapse of the supramolecular nanomesh can produce or destroy, respectively, the physical obstacle for ATPase so as to control the ATPase motion in an off/on manner. Furthermore, this switching of the F1 -ATPase motion could be spatially restricted by using a microheating device. The integration of biomolecules and hard materials, interfaced with intelligent soft materials such as supramolecular hydrogels, is promising for the development of novel semi-synthetic nano-biodevices. [source] Description and characterization of a chamber for viewing and quantifying cancer cell chemotaxisCYTOSKELETON, Issue 1 2005Lilian Soon Abstract Direct observations of cancer cell invasion underscore the importance of chemotaxis in invasion and metastasis. Yet, there is to date, no established method for real-time imaging of cancer chemotaxis towards factors clinically correlated with metastasis. A chamber has been designed and tested, called the Soon chamber, which allows the direct observation and quantification of cancer cell chemotaxis. The premise for the design of the Soon chamber is the incorporation of a dam, which creates a steep gradient while retaining stability associated with a pressure-driven system. The design is based on the characteristics of cancer cell motility such as relatively low speeds, and slower motility responses to stimuli compared to classical amoeboid cells like neutrophils and Dictyostelium. We tested MTLn3 breast carcinoma cells in the Soon chamber in the presence of an EGF gradient, obtaining hour-long time-lapses of chemotaxis. MTLn3 cells migrated further, more linearly, and at greater speeds within an EGF gradient compared to buffer controls. Computation of the degree of orientation towards the EGF/buffer source showed that MTLn3 cells were significantly more directional toward the EGF gradient compared to buffer controls. Analysis of the time-lapse data obtained during chemotaxis demonstrated that two populations of cancer cells were present. One population exhibited oscillations in directionality occurring at average intervals of 12 min while the second population exhibited sustained high levels of directionality toward the source of EGF. This result suggests that polarized cancer cells can avoid the need for oscillatory path corrections during chemotaxis. Cell Motil. Cytoskeleton 62:27,34, 2005. © 2005 Wiley-Liss, Inc. [source] The food habits of a Malagasy Giant: Hipposideros commersoni (E. Geoffroy, 1813)AFRICAN JOURNAL OF ECOLOGY, Issue 3 2009Andrinajoro A. Rakotoarivelo Abstract Hipposideros commersoni is a large microchiropteran bat endemic to Madagascar. We analysed fragments of its prey from faeces and from underneath feeding perches to describe its diet from four sites. Diet was similar across sites and Coleoptera was the main prey item by percentage volume (75%), followed by Hemiptera (13%). Carabidae and Scarabidae were the most frequent coleopterans found in the diet. Direct observations (n = 3) were made of bats flying short distances from perches along forest trails to prey on Cicadidae (c. 20 mm in length) located on tree trunks. There were differences in the composition of faecal samples collected form netted bats and pellets collected under feeding perches, with the latter consisting of more Blattoptera (Blattellidae ,cockroaches'). Hipposideros commersoni appears to have a unique foraging behaviour and diet among Malagasy microchiropterans and its preference for certain Coleoptera and other large invertebrates may account for reported seasonal variation in body fattening and activity. Résumé Hipposideros commersoni est une grande chauve-souris microchiroptère endémique de Madagascar. Nous avons analysé des fragments de proies à partir des excréments et sous les perchoirs où elle se nourrit pour décrire son régime alimentaire sur cinq sites. Le régime était semblable sur tous les sites, et les coléoptères constituent les proies principales en pourcentage du volume (75%), suivis par les hémiptères (13%). Les carabidés et les scarabidés sont les coléoptères trouvés le plus fréquemment dans le régime alimentaire. Des observations directes (n = 3) ont été faites de chauves-souris volant sur de courtes distances à partir de leur perchoir le long de pistes forestières pour attraper des cicadidés (env. 20 mm. de long) posés sur des troncs d'arbres. Il y avait des différences dans la composition des échantillons de crottes récoltés à partir de chauves-souris capturées dans des filets et celle des pelotes récoltées sous les perchoirs, ces dernières contenant plus de Blattoptères (Blattellides , cancrelats). Hipposideros commersoni semble avoir un comportement et un régime alimentaires uniques parmi les microchiroptères malgaches, et sa préférence pour certains coléoptères et pour d'autres grands invertébrés pourrait intervenir dans les variations saisonnières rapportées du taux de graisse dans le corps et de l'activité. [source] The role of Steller sea lions in a large population decline of harbor sealsMARINE MAMMAL SCIENCE, Issue 4 2010Elizabeth A. Mathews Abstract We provide the first direct evidence that Steller sea lions will prey on harbor seals. Direct observations of predation on marine mammals at sea are rare, but when observed rates of predation are extrapolated, predation mortality may be found to be significant. From 1992 to 2002, harbor seals in Glacier Bay declined steeply, from 6,200 to 2,500 (,65%). After documenting that Steller sea lions were preying on seals in Glacier Bay, we investigated increased predation by sea lions as a potential explanation for the large decline. In five independent data sets spanning 21,25 yr and including 14,308 d of observations, 13 predation events were recorded. We conducted a fine-scale analysis for an intensively studied haul-out (Spider Island) and a broader analysis of all of Glacier Bay. At Spider Island, estimated predation by sea lions increased and could account for the entirety of annual pup production in 5 of 8 yr since 1995. The predation rate, however, was not proportional to the number of predators. Predation by Steller sea lions is a new source of mortality that contributed to the seal declines; however, life history modeling indicates that it is unlikely that sea lion predation is the sole factor responsible for the large declines. [source] Use of wild and cultivated foods by chimpanzees at Bossou, Republic of Guinea: feeding dynamics in a human-influenced environmentAMERICAN JOURNAL OF PRIMATOLOGY, Issue 8 2009Kimberley J. Hockings Abstract Increased human population growth and more conversions of natural habitat to agricultural land have resulted in greater proximity between humans and nonhuman primate species. Consequent increases in resource competition including crop-raiding are a by-product of both natural resources becoming less available and the nutritional benefits of cultivated foods becoming more known to the nonhuman primates. Chimpanzees at Bossou in the Republic of Guinea, West Africa, consume 17 different types of cultivated foods that are grown extensively throughout their small, fragmented home range. Direct observations of feeding behavior conducted over an 18-month period revealed that during specific months crops account for up to one quarter of chimpanzee feeding time, with higher overall crop-raiding levels throughout the periods of wild fruit scarcity. Some cultivated foods, especially sugar fruits, are mostly fallback foods, whereas others, such as rice pith (Oryza sp.) and maize (Zea mays), are consumed according to their availability even when wild foods are abundant. These findings highlight the importance of both crop choice by farmers and a thorough understanding of the ecology of resident primate species when establishing land management techniques for alleviating human,primate conflict. Am. J. Primatol. 71:636,646, 2009. © 2009 Wiley-Liss, Inc. [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||