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41.
Landsat TM and ETM+ imagery was used to distinguish areas of high vs. low cover of Amur honeysuckle (Lonicera maackii), taking advantage of the late leaf retention of this invasive shrub. L. maackii cover was measured in eight stands and compared to 15 Landsat 5 TM and Landsat 7 ETM+ images from spring and autumn dates from 1999 to 2006. Jeffries–Matusita (JM) distance calculations showed potential separability between high vs. low/zero cover classes of L. maackii on some late fall images. The Soil Adjusted Atmospheric Resistant Vegetation Index (SARVI2) revealed higher levels of green biomass in high L. maackii cover plots than low/zero cover plots for November images only. These findings justify further investigation of the effectiveness of late fall images to map the historical spread of L. maackii and other forest understory invasives with similar phenology. 相似文献
42.
Cell division in prokaryotes is mediated by the septal ring. In Escherichia coli, this organelle consists of several essential division proteins, including FtsZ, FtsA, and ZipA. To gain more insight into how the structure is assembled, we studied the interdependence of FtsZ, FtsA, and ZipA localization using both immunofluorescence and Gfp tagging techniques. To this end, we constructed a set of strains allowing us to determine the cellular location of each of these three proteins in cells from which one of the other two had been specifically depleted. Our results show that ZipA fails to accumulate in a ring shape in the absence of FtsZ. Conversely, depletion of ZipA does not abolish formation of FtsZ rings but leads to a significant reduction in the number of rings per unit of cell mass. In addition, ZipA does not appear to require FtsA for assembly into the septal ring and vice versa. It is suggested that septal ring formation starts by assembly of the FtsZ ring, after which ZipA and FtsA join this structure in a mutually independent fashion through direct interactions with the FtsZ protein. 相似文献
43.
Hale J.G. Pollick F.E. 《IEEE transactions on systems, man and cybernetics. Part C, Applications and reviews》2005,35(4):512-521
"Sticky Hands" is a physical game for two people involving gentle contact with the hands. The aim is to develop relaxed and elegant motion together, achieve physical sensitivity-improving reactions, and experience an interaction at an intimate yet comfortable level for spiritual development and physical relaxation. We developed a control system for a humanoid robot allowing it to play Sticky Hands with a human partner. We present a real implementation including a physical system, robot control, and a motion learning algorithm based on a generalizable intelligent system capable itself of generalizing observed trajectories' translation, orientation, scale and velocity to new data, operating with scalable speed and storage efficiency bounds, and coping with contact trajectories that evolve over time. Our robot control is capable of physical cooperation in a force domain, using minimal sensor input. We analyze robot-human interaction and relate characteristics of our motion learning algorithm with recorded motion profiles. We discuss our results in the context of realistic motion generation and present a theoretical discussion of stylistic and affective motion generation based on, and motivating cross-disciplinary research in computer graphics, human motion production and motion perception. 相似文献
44.
45.
Peter Hale Iain Mactaggart Martin Shaw 《Quality and Reliability Engineering International》1986,2(3):165-170
This paper describes, and gives a mathematical analysis of, the performance of two makes of CRT bleed resistors which exhibit markedly different characteristics under heat soak conditions. By examining the observed resistance changes with temperature, and relating these to the Arrhenius equation, the reaction activation energies can be determined. Further analysis of the power consumption characteristics of the resistors leads to the establishment of resistance-time curves for both makes of resistor. These indicate very different conclusions than might otherwise have been drawn from initial test data. Finally the Monte Carlo' simulation technique is used to determine the most likely survival characteristics in a field situation, and a quantitative assessment of the reliability of CRTs using these bleed resistors is given. The construction of the resistor body is common to both makes and comprises a resistor substrate enclosed within an overcoat which is in turn encapsulated in epoxy. One make (type A) is a glass thick film structure, whereas the other is a polymer thick film system. 相似文献
46.
C. Hale BSc K. Kaur BSc PhD N. Jones BSc B. Oliver 《Water and Environment Journal》2005,19(4):376-383
Llangefni WwTW receives discharge from the rural town of Llangefni and the local industrial estate and to date this is the first and only BNR plant in Wales. The consents from March 2003 included a reduction in ammonia (NH4 _N) to 1.5 mg/l, suspended solids to 20 mg/l (SS) and Biological Oxygen Demand (BOD) to 7 mg/l and included a new Phosphate (PO4 _P) standard of 2 mg/l. The process selected to meet the new consents was Biological Nutrient Removal (BNR) and was unusual as it was for a small, rural wastewater treatment plant that receives about 26% of its flow from an industrial estate.
During commissioning, the plant produced an average phosphate concentration of 1.0 mg/l and an ammonia concentration of 0.7 mg/l. It was confirmed that to achieve consistent phosphate removal a BOD:P ratio greater than 20:1 is required along with a high VFA (Volatile Fatty Acids) concentration of 200–300 mg/l. 相似文献
During commissioning, the plant produced an average phosphate concentration of 1.0 mg/l and an ammonia concentration of 0.7 mg/l. It was confirmed that to achieve consistent phosphate removal a BOD:P ratio greater than 20:1 is required along with a high VFA (Volatile Fatty Acids) concentration of 200–300 mg/l. 相似文献
47.
JF de Kroon RA de Paus HC Kluin-Nelemans PM Kluin CA van Bergen AJ Munro G Hale R Willemze JH Falkenburg 《Canadian Metallurgical Quarterly》1996,24(8):919-926
Severe combined immunodeficient (Scid) mice inoculated with the human (t(14;18)-positive B cell lines DoHH2 and BEVA develop lethal systemically disseminated lymphoma (de Kroon et al., Leukemia 8:1385, and Blood 80 [suppl 1]:436). These models were used to study the therapeutic effect of rat-anti-human CD52 (Campath-1G) or CD45 monoclonal antibodies (mAbs) on systemically disseminated tumor cells and on tumor cells present in solid tumor masses. Both mAbs were effective in inhibiting growth of systemically disseminated malignant cells. When treatment with anti-CD52 or anti-CD45 mAbs at a dose of 30 micrograms/mouse/d for 4 days was started 24 hours after intravenous inoculation of human DoHH2 or BEVA cells, a 3-log kill of tumor cells was observed as measured by prolonged survival. After treatment, surviving animals injected with high numbers of BEVA cells showed tumor masses in liver, kidney, and mesenteric lymph nodes. In contrast to nontreated animals, however, only low numbers of malignant cells were found in peripheral blood, and bone marrow was free of tumor cells. Similarly, after mAb treatment of mice inoculated subcutaneously (sc) with DoHH2 cells, no tumor cells could be found in the bone marrow, and few DoHH2 cells could be detected in the peripheral blood, spleen, liver, kidney, or lung. In contrast, tumor cells present in subcutaneous tumors and axillary lymph nodes were relatively unaffected by mAb therapy. The presence of rat immunoglobulin (Ig) could be demonstrated on surviving tumor cells. The presence of murine macrophages in areas in these tumors that were depleted of DoHH2 cells suggested that the mAb-mediated antitumor effect observed in the Scid mouse model is mediated by cellular mechanisms. Apparently these mechanisms were not sufficient to eliminate the fast-growing tumor cells present in the protected sites. Our results indicate that treatment with anti-CD52 or anti-CD45 mAbs potentially may be useful as adjuvant immunotherapy for systemically disseminated B cell lymphoma. 相似文献
48.
Aged Tg2576 mice show abnormalities in hippocampal morphology and physiology and display behavioral deficits in spatial navigation tasks consonant with a deficit in the functional properties of the hippocampus. However, the nature of the spatial representations disrupted by the "Swedish" mutation of the amyloid precursor protein (APPswe) is unclear. In an effort to characterize the memory deficits in Tg2576 mice, the spontaneous object exploration paradigm was used to interrogate spatial and object memory in mice. With object arrays of comparable size, 16-month-old Tg2576 mice showed a normal object familiarity/novelty effect but impaired memory for the location of objects when 2 objects exchanged locations (topological transformation; Experiment 1). In contrast, Tg2576 mice showed preferential exploration of familiar objects when they were moved to previously unoccupied locations (Experiment 2), irrespective of whether the transformation altered the metric properties of the object array (Experiments 3). These results suggest that Tg2576 mice are able to form representations of the identity of objects and a memory of the spatial organization of objects in an arena. In contrast, conjunctive memory for specific object-location associations is severely impaired in aged Tg2576 mice. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
49.
M. Lee E. F. Koch T. E. Hale 《International Journal of Refractory Metals and Hard Materials》1996,14(5-6):335-343
The microstructure of the interface bonding zone of the Al2O3 coating and the cemented carbide substrate of a coated tool has been analyzed using transmission electron microscopy. It is concluded that a complex aluminium-tantalum oxide of rutile type AlTaO4 contributes to the strong bonding owing to the similarity of its crystal structure to TiO2. Synthesis of experimental tools with other oxides very similar to AlTaO4 as bonding material confirmed this hypothesis. 相似文献
50.
The majority of gene therapy protocols have used or plan to use retroviral vectors based upon murine leukaemia virus. These vectors are able to infect many different cell types, and the retroviral promoter, which is often used to control the expression of a therapeutic gene, is active in a wide range of different cell types. Safe and efficient gene transfer systems, whether based upon retroviruses or other agents, should deliver beneficial genes only to cells that require their therapeutic action, and these genes ideally should be expressed exclusively in such cells. In this paper, strategies for redirecting the infection spectrum of retroviral vectors in order to obtain cell-targeted gene delivery are discussed. These strategies include the engineering of the retroviral envelope protein, which, together with the availability of its cognate receptor, determines infectivity, and the use of proteins from other enveloped viruses of both retroviral and nonretroviral origin in the cell lines used to produce retroviral vector virus particles. Expression targeting can be achieved by limiting the expression of therapeutic genes to the cell type(s) of interest using promoters from genes that are normally active in these cells. This approach to targeting is illustrated using promoters from genes expressed in either the liver, the pancreas or the mammary gland as a means to limit gene expression specifically to the cell types that make up these organs. The successful utilization of new generations of targeted retroviral vectors in the clinic may well pave the way for superior gene delivery systems of the future that seek out their target cell, delivering a therapeutic gene to and expressing it only in such cells. 相似文献