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91.
David A Winter Arthur O Quanbury Douglas A Hobson H.Grant Sidwall Gary Reimer Brian G Trenholm Thomas Steinke Henry Shlosser 《Journal of biomechanics》1974,7(6):479-486
A T.V.-computer system for the measurement and analysis of the kinematics of normal and abnormal locomotion has been developed which has the following characteristics: minimum encumberment to the subject or patient, determination of absolute coordinates of anatomical landmarks, analysis of 3 or 4 strides, and automation of data conversion and analysis. Analysis techniques have been developed which take advantage of the accuracy of the marker coordinates, and with suitable application of noise reduction filtering, permit direct calculation of velocities and accelerations (both linear and angular). Examples of some of these derived parameters vs time are presented. The results of a statistical study on a group of normal subjects walking at slow, comfortable and fast cadences yield the ranges of many velocities and accelerations not previously available. 相似文献
92.
Relationship between bacteria and ciliate protozoa in the sheep rumen 总被引:14,自引:0,他引:14
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Flyway population delineation in Taiga Bean Geese Anser fabalis fabalis revealed by multi‐element feather stable isotope analysis
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Anthony D. Fox Keith A. Hobson Adriaan de Jong Kevin J. Kardynal Geoff Koehler Thomas Heinicke 《Ibis》2017,159(1):66-75
Fundamental to effective management of migratory waterbird populations is an understanding of their flyway delineation. Taiga Bean Geese Anser fabalis fabalis wintering in NW Denmark, Scotland and England are considered to originate from northern and central Sweden, southern and central Norway (‘Western flyway’), those wintering in southern Sweden, NE and southern Denmark are considered to originate from northern Fennoscandia and western Russia (‘Central flyway’), and those wintering in eastern Germany and Poland (which show far less favourable conservation status) are thought to come from western Siberia (‘Eastern 1 flyway’), although evidence to demonstrate this has largely been lacking. Evidence for different natal and moult origins of Taiga Bean Geese was investigated using stable isotope analyses of feathers of four elements (δ2H, δ13C, δ15N and δ34S). There were significant differences in isotopic composition of feathers from Swedish (Central) and German (Eastern 1) wintering populations and those moulting in Sweden in late summer (Western), which validated the three proposed major management flyway units above. The strong continental gradient in the stable hydrogen isotope ratios in precipitation (δ2Hp) across the region was used to assign wintering birds geospatially to natal and moulting origin, indicating separate natal and moulting areas for German (n = 37, from western Siberia) and Swedish (n = 20, Fennoscandia and more western Russia) wintering birds. These results confirm the largely discrete nature of these three flyways and contribute significantly to our ability to deliver effective targeted and appropriate research, monitoring and management actions throughout the ranges of these flyways. 相似文献
97.
Karagiannis P Singer J Hunt J Gan SK Rudman SM Mechtcheriakova D Knittelfelder R Daniels TR Hobson PS Beavil AJ Spicer J Nestle FO Penichet ML Gould HJ Jensen-Jarolim E Karagiannis SN 《Cancer immunology, immunotherapy : CII》2009,58(6):915-930
Trastuzumab (Herceptin), a humanized IgG1 antibody raised against the human epidermal growth factor receptor 2 (HER2/neu), is the main antibody in clinical use against breast cancer. Pre-clinical evidence and clinical studies indicate that trastuzumab employs several anti-tumour mechanisms that most likely contribute to enhanced survival of patients with HER2/neu-positive breast carcinomas. New strategies are aimed at improving antibody-based therapeutics like trastuzumab, e.g. by enhancing antibody-mediated effector function mechanisms. Based on our previous findings that a chimaeric ovarian tumour antigen-specific IgE antibody showed greater efficacy in tumour cell killing, compared to the corresponding IgG1 antibody, we have produced an IgE homologue of trastuzumab. Trastuzumab IgE was engineered with the same light- and heavy-chain variable-regions as trastuzumab, but with an epsilon in place of the gamma-1 heavy-chain constant region. We describe the physical characterisation and ligand binding properties of the trastuzumab IgE and elucidate its potential anti-tumour activities in functional assays. Both trastuzumab and trastuzumab IgE can activate monocytic cells to kill tumour cells, but they operate by different mechanisms: trastuzumab functions in antibody-dependent cell-mediated phagocytosis (ADCP), whereas trastuzumab IgE functions in antibody-dependent cell-mediated cytotoxicity (ADCC). Trastuzumab IgE, incubated with mast cells and HER2/neu-expressing tumour cells, triggers mast cell degranulation, recruiting against cancer cells a potent immune response, characteristic of allergic reactions. Finally, in viability assays both antibodies mediate comparable levels of tumour cell growth arrest. These functional characteristics of trastuzumab IgE, some distinct from those of trastuzumab, indicate its potential to complement or improve upon the existing clinical benefits of trastuzumab. 相似文献
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Using stable-isotope analysis of feathers to distinguish moulting and breeding origins of seabirds 总被引:1,自引:0,他引:1
To determine whether stable isotope measurements of bird feathers can be used to identify moulting (interbreeding) foraging
areas of adult seabirds, we examined the stable-carbon (δ13C) and nitrogen (δ15N) isotopic composition of feathers of chicks and adults of black-browed albatrosses (Diomedea melanophrys) from Kerguelen Islands, southern Indian Ocean. Albatross chicks are fed primarily fish (75% by mass), the diet being dominated
by various species of the family Nototheniidae and Channichthyidae which commonly occur in the shelf waters in the vicinity
of the colony. δ13C and δ15N values in chick feathers, which are grown in summer in the breeding area, were lower than values in adult feathers, which
are grown in winter (δ13C: –19.6‰ versus –17.6‰ and δ15N: 12.4‰ versus 15.7‰, respectively). No differences in δ13C and δ15N values were found in adult wing feathers moulted in 1993 and 1994 and in adult feathers formed at the beginning, middle
and end of the 1994 moulting period. These data are consistent with adults moulting in the same area and feeding at the same
trophic level from one year to the next and with no major changes in foraging ecology within a given moulting season; they
suggest that foraging grounds were different in summer and winter and that these differed in their stable-isotope signature.
Changes in both feather δ13C and δ15N values indicated feeding south of the Subtropical Front (STF) during chick rearing, which is in agreement with the known
foraging ecology at this time and feeding north of the STF during moult. This, together with band recoveries from adult birds,
indicates that black-browed albatrosses from Kerguelen Islands wintered in subtropical waters off southern Australia. The
stable-isotope markers in feathers, therefore, have the potential for locating moulting areas of migratory seabird species
moving between isotopically distinct regions and for investigating seabirds’ foraging ecology during the poorly known interbreeding
period. Such information is needed for studies of year-round ecology of seabirds as well as for their conservation and the
long-term monitoring of the pelagic environment.
Received: 28 June 1999 / Accepted: 14 September 1999 相似文献
100.
Interest in the use of low-copy nuclear genes for phylogenetic analyses of
plants has grown rapidly, because highly repetitive genes such as those
commonly used are limited in number. Furthermore, because low- copy genes
are subject to different evolutionary processes than are plastid genes or
highly repetitive nuclear markers, they provide a valuable source of
independent phylogenetic evidence. The gene for granule-bound starch
synthase (GBSSI or waxy) exists in a single copy in nearly all plants
examined so far. Our study of GBSSI had three parts: (1) Amino acid
sequences were compared across a broad taxonomic range, including grasses,
four dicotyledons, and the microbial homologs of GBSSI. Inferred structural
information was used to aid in the alignment of these very divergent
sequences. The informed alignments highlight amino acids that are conserved
across all sequences, and demonstrate that structural motifs can be highly
conserved in spite of marked divergence in amino acid sequence. (2)
Maximum-likelihood (ML) analyses were used to examine exon sequence
evolution throughout grasses. Differences in probabilities among
substitution types and marked among-site rate variation contributed to the
observed pattern of variation. Of the parameters examined in our set of
likelihood models, the inclusion of among-site rate variation following a
gamma distribution caused the greatest improvement in likelihood score. (3)
We performed cladistic parsimony analyses of GBSSI sequences throughout
grasses, within tribes, and within genera to examine the phylogenetic
utility of the gene. Introns provide useful information among very closely
related species, but quickly become difficult to align among more divergent
taxa. Exons are variable enough to provide extensive resolution within the
family, but with low bootstrap support. The combined results of amino acid
sequence comparisons, maximum-likelihood analyses, and phylogenetic studies
underscore factors that might affect phylogenetic reconstruction. In this
case, accommodation of the variable rate of evolution among sites might be
the first step in maximizing the phylogenetic utility of GBSSI.
相似文献